This glossary is provided as a convenience and has been accessed from the
'net for your use. Credit for this comprehensive glossary should go to the
Like many professions, stage and studio venues have created terms for things
that appear only in that field, or adapted terms from other sources. The
following is offered as a primer on many of those terms unique or unusual to
theatre and television, with a tendency towards those used in the United States.
Hope you find it useful and, if you know of a term that's not included, you'll
let us know about it: drop us a comment.
A-TYPE : See Jack
ADAM : See Digital Recording.
ADAPTOR (or Splitter) : Connector which allows two or more electrical
devices to be connected to a single power outlet. The connection is parallel,
that is, each device is fed the same voltage, but the current is divided
between them. Sometimes known as a "Twofer". See Series Splitter,
Jumper and Grelco.
ADAT : See Digital Recording.
AB POWERING : See Phantom Power.
ABTT : The Association of British Theatre Technicians..
ACOUSTICS : The behaviour of sound and its study. The acoustics of a room
depend on its size and shape and the amount and position of sound-absorbing
and reflecting material.
ACOUSTIC PICK-UP : See Pick-Up.
ACT DROP : Front cloth or tabs lowered during intervals. Especially
pantomime / musicals.
ACTING AREA : That area within the performance space within which the actor
may move in full view of the audience. (Also name of early Strand
down-lighting floodlight - known as "Ack Ack").
ACTIVE : A piece of circuitry is termed active if it needs a power supply
for it to function. (Active DI box, Active crossover etc.) Circuitry that
needs no additional power supply is termed passive (eg resistors &
capacitors in a crossover). Passive circuits use the electrical sound signal
itself to operate the components. OR A piece of circuitry is termed active if
it amplifies a signal supplied to it. A passive circuit does not increase the
level of a signal.
ADDITIVE COLOUR MIXING : See Colour Mixing.
ADVANCE BAR : Lighting bar positioned just downstage of the proscenium
AERIAL : Cable or rod used to send and receive radio signals (connected to
transmitter and receiver or tuner).
AERO : A type of high intensity Par lamp that derives its name from its use
as an aircraft landing lamp. The true Aero is 28V and 250W, although there are
many variations. The lamp has a very tight beam.
AETTI : Arts & Entertainment Technical Training Initiative (UK).
AGC : Automatic Gain Control. Circuitry within recording equipment which
compensates for differences in volume in the incoming sound signal by
adjusting the gain automatically. Helps to reduce wild swings in volume.
AISLE : A passage through seating.
A.J. : Jargon for an Adjustable Spanner.
A.L.D. :Association of Lighting Designers.(UK)
AMP :Abbreviation for ;
1) AMPERE, the standard unit for measurement of electrical current passing
through a circuit. Cables, fuses and switches are designated by their current
carrying capacity. Square pin plugs are rated at 13 Amps maximum and Round pin
plugs at either 5 Amps or 15 Amps maximum, depending on the size of the pins.
If a cable rated at 5 Amps is used with a load of 15 Amps, the cable will
overheat and possibly catch fire.
2) AMPLIFIER - sound equipment that converts the low voltage, low current
signal from a tape deck, mixer etc. into a higher current signal suitable for
driving speakers. See Power Amplifier, Crossover.
AMPLITUDE : The strength of a vibrating wave ; in sound, the loudness of
ANALOGUE SIGNAL (See Digital) : A continuously variable signal that can
have any value over a given range. For example, an analogue voltage within the
range 0 to 10 Volts can have values of 0, 2, 8.785 or any value between. Most
dimmers require an analogue voltage in order to operate (from 0 to -10V or 0
to +10V depending on the manufacturer). Most lighting control desks produce a
digital multiplexed output, which is converted by a demux box to an analogue
signal for the dimmer. See also Digital dimmer.
ANIMATION DISC : See Effects.
A.N.S.I. : American National Standards Institute.
APRON : Section of the stage floor which projects towards or into the
auditorium. In proscenium theatres, the part of the stage in front of the
house tabs, or in front of the proscenium arch.
ARC LIGHT : See Discharge lamp.
ARCHITECTURAL LAMP : A type of linear filament lamp with contacts at 90
degrees to the filament which can gives the appearance of a continuous line of
light (similar to neon, but dimmable).
ARCLINE (Trade Name) : A coloured plastic tube containing a number of small
strobe units which, when triggered, flash in sequence down the tube. Many
tubes can be connected together.
ARENA : Form of stage where the audience are seated on at least two
(normally three, or all four) sides of the whole acting area. See Thrust.
ASM : Assistant Stage Manager.
ATTENUATE : To reduce the intensity of a sound signal.
ATMOSPHERE : The normal background sound at any location.
AUDITORIUM : The part of the theatre accommodating the audience during the
performance. Sometimes known as the "house".
AUTOMATIC STOP : Many reel-to-reel tape players for theatrical use have a
facility that stops the tape mechanism when a piece of clear leader passes a
detector adjacent to the erase head. This can be used to cue the tape up ready
to start the next effect.
1) Facility available on larger sound mixing desks allowing channel muting
or even fader moves to be taken under the control of a computer to ensure
accurate and repeatable mixing.
2) Describes the method used instead of stage crew for moving bits of set
around shows with a big budget.
AUXILIARY OUTPUT or SEND : An additional output from a sound desk which can
be used for foldback or monitoring without tying up the main outputs. Each
input channel will have a path to the Aux buss. Also used for feeding a signal
to an effects processor. See Auxiliary Return.
AUXILIARY INPUT or RETURN : A route back into the sound desk for a signal
sent to a piece of outboard equipment via an auxiliary send.
The term also refers to the mounting location of head blocks at the top of
a counterweight system, typically as part of the phrase "head block beam".
BACK CLOTH : See Cloth.
BACKFLAP : Hinge frequently used in Scenic Construction.
1) Scenic piece as a backing behind an opening in the set (window etc.) which
hides the technical areas beyond.
2) The money invested in a commercial production (by a Backer).
BACKLIGHT : Light coming from upstage, behind scenery or actors, to sculpt
and separate them from the background
BACK PROJECTION : See Projection.
BACKSTAGE : The part of the stage and theatre which is out of the sight of
the audience. The service areas of the theatre.
BACK-UP : A section of a lighting control board (sometimes a separate unit)
which provides an alternative method of control should the main board fail.
1) A sheet of material used to prevent a spill of light in a lantern or in
part of a set.
2) A panel in a loudspeaker cabinet designed to reduce back interference
noise by isolating the front and rear of the loudspeaker diaphragm.
3) What most of this jargon will do to any non-technical theatrical type.
BAKELITE :(Trade Name) : Hard insulating plastic-like material used in making
electrical accessories (e.g. plugtops, lampholders etc.)
BALANCED LINE : A method of carrying sound signals which reduces interference
by using a third conductor, the shield. The two inner conductors carry the same
sound signal, one is positive and the other is negative. Any interference
induced into the cable is equal and opposite in each of the inner conductors and
is cancelled out. It is important to use balanced lines when carrying low level
signals (e.g. microphones) along long cable runs. See unbalanced line.
BALLAST : A unit used in conjunction with discharge lamps containing
capacitors, inductors and other start-up circuitry. The inductor is initially
used to develop a high potential to strike the discharge and is then used to
limit the current flow while the lamp is lit.
BANTAM : See Jack.
The horizontal metal tube (usually 48mm in external diameter) hung from
flying lines (or forming part of a grid) from which lighting equipment and
scenery etc. may be suspended. Also known as a Barrel. When vertical, known as a
Boom. In the US, known as a Pipe.
BAR BELLS :
are rung in public areas of the theatre to warn the audience that the
performance is about to start/continue. Usuallyoperated from the prompt corner
and sometimes followed by Front of House Calls. The bells are also used as a
warning to FOH staff that the interval is about to commence or that the show is
about to end.
BARNDOORS : A rotatable attachment consisting of two ir four metal flaps
which is fixed to the front of a Fresnel or PC type lanternto reduce the beam
spread in one or more directions.
BASE PLATE : A metal plate which prevents damage to floors when using
scaffolding or trussing.
BASS : Lower end of the musical scale. In acoustics, the range (below about
200Hz) in which there are difficulties, principally in the reproduction of
sound, due to the large wavelengths involved.
BASS BIN : Speaker cabinet containing Woofer designed for Bass sound
reproduction (see also Subwoofer).
BASTARD SIDE (B.S.) : Terminology used when the Prompt corner is Stage Right.
Stage Left is then known as Opposite Bastard (O.B.)
1) Timber at the top and bottom of a cloth. A Sandwich batten is used to
carry a hanging cloth. It comprises two flat pieces of timber screwed together
with the edge of the cloth between them.
2) Timber used for joining flats together for flying.
3) Compartmentalised floodlights set up so as to allow colour mixing. See
also groundrow. Low voltage battens are commonly used as light curtains &
for colour washes.
BC HOLDER : Type of domestic lampholder that has largely been replaced by the
ES (Edison Screw) and the GES (Goliath Edison Screw) for general lighting
applications in the theatre. Stage lighting equipment uses prefocus lamp bases.
(Most types of Festoon still use BC holders.)
BEAM ANGLE : The angle of the cone of light produced by a lantern. Defined as
the angle within which the lowest intensity in a beam of light from a lantern is
not less than one-tenth of the maximum.
BEAMLIGHT : Flood lantern which uses a parabolic reflector and a low voltage
high intensity lamp to produce an intense near-parallel beam.
BECTU : Broadcasting, Entertainment, Cinematograph and Theatre Union. The UK
entertainment technicians union.
BEGINNERS : A call given by the DSM to bring those actors who appear in the
first part of a play to the stage. e.g. "Act One Beginners to the stage,
please". The actors/actresses are then called by name.
BELL BOARD : A live sound effects board on which are mounted a number of
different types of doorbells / phone bells etc. Usually operated by stage
BI-AMPLIFICATION : A way of optimising the efficiency of a speaker system by
separately amplifying the High Frequency (HF) and Low Frequency (LF) portions of
the sound signal and sending them down two pairs of cables to the speaker.
Multipin Speakon connectors have been developed to do this.
BIFOCAL SPOT : Profile lantern with two sets of shutters, one of which
produces a hard edge, and one a soft edge. Not necessary in zoom profiles,
because this requirement is fulfilled by two lenses.
BILLY BLOCK : A pulley on a short length of rope used to divert the pull of a
working rope, or to suspend a single item in storage.
BIRDIE : A compact display luminaire containing a Par 16 lamp. So called
because it is similar to, but much smaller than, the Parcan, and is hence
"one under Par".
BLACK HOLE : Accidentally unlit portion of the stage.
BLACK LIGHT : See Ultra-Violet.
1) Black clothing worn by stage management during productions.
2) Any black drapes or tabs, permanently or temporarily rigged. Used for
masking technical areas.
BLACKOUT : Complete absence of stage lighting. Blue working lights backstage
should remain on and are not usually under the control of the board, except
during a Dead Blackout (DBO), when there is no onstage light. Exit signs and
other emergency lighting must remain on at all times.
BLEECON : Trade name for a type of low voltage 8 pin connector which is
similar to the audio DIN plug. Used most often for carrying signals from
analogue lighting control desks to dimmers or to demux boxes. Originally
manufactured by Belling and Lee.
BLEED : Dimmers which are incorrectly trimmed are said to bleed. That is, the
dimmer still gives a small output, causing the lantern to glow, when the control
signal is at a minimum.
BLEED THROUGH : Transformation from a scene downstage of a gauze to another
scene upstage, by slowly crossfading lighting from downstage to upstage. If a
gauze is lit steeply, or from the sides, it will appear solid. If this light is
turned off and light added to the set upstage of it, it will disappear.
BLINDERS : Lamps arranged around the stage directed into the auditorium ,
originally to prevent spectators seeing the stage during scene changes when the
house tabs were not lowered. Now used for effect in rock concerts etc.
BLIND PLOTTING : The facility on some lighting control desks for the operator
to make changes to the plot, without affecting the state on stage.
BLOCK : Frame in which one or more pulley wheels (sheaves) are mounted.
BLOCKING : The process of arranging moves to be made by the actors during the
play, recorded by stage management in the prompt script.
BLUES : Blue lights used backstage in a performance situation. See also
BNC: Coaxial connector used for carrying a composite video signal or radio
BOARD : The main control for the stage lighting. Originally known as the
switchboard or dimmerboard, it is now usually remote from the dimmers. The
lighting operator for a show is said to be "on the board".
BOMB TANK : Metal bin or box covered with fine mesh in which Theatrical
Maroons can be safely detonated.
BOOK : See Prompt Book.
BOOK FLAT : Two-fold piece of scenery. Book flats are free-standing when
angled open, allowing quick setting and compact storage. Booking describes the
action of opening or closing a book flat.
1) Vertical scaffolding pole (usually 48mm diameter) on which horizontal boom
arms can be mounted, carrying lanterns. Often used behind wings for
side-lighting etc. Booms have a base plate or stand at the bottom and are tied
off to the grid or fly floor at the top (not always necessary for short booms).
Booms can also be fixed to the rear of the procenium arch (Pros. Boom) or
hanging from the ends of lighting bars. Sometimes known as a light tree (US).
2) An arm mounted on a microphone stand.
BOOM ARM : See Boom.
BORDER : A narrow horizontal masking piece (flattage or cloth), normally of
neutral colour to mask the lighting rig and flown scenery from the audience, and
to provide an upper limit to the scene. Often used in conjunction with legs.
BOSS PLATE : Metal plate fixed to the stage floor into which a bolt can be
screwed for fixing scenery.
BO'SUN'S CHAIR : A small seat or cradle rigged on a rope over a pulley
whereby a technician may be hoisted to work at an otherwise inaccessible
BOTTLESCREW : (Also Bottle Strainer) Threaded device which is used to tension
a wire, or to provide an adjustable link in a cable, to fine-tune the height of
flown scenery. (Known in the USA as a Turnbuckle)
1) Diffuse light that has been reflected from the stage, walls, cyc etc.
2) Describes the fast in/out movement of "bouncing" flown house
tabs, used during curtain calls.
3) This facility is available on many multitrack tape machines. Describes the
mixing down of multiple sounds from different tracks onto one track, hence
freeing up the other tracks to be re-used. Allows many sounds to be recorded
onto one tape.
BOUNDARY MIC. : A microphone mounted on a flat plate which acts as a
reflective surface directing sound into the mic capsule. Used for general
pick-up over a large area. See PCC, PZM.
BOX SET : Naturalistic setting of a complete room built from flats with only
the side nearest the audience (the fourth wall) missing.
1) Angled strengthening timber within a flat.
2) Support for scenery (flattage) on stage
a. Extendible, hooking into a screw eye on the flat and being weighted to the
floor (commonly known as a "Stage Brace")
b. French, right-angled non adjustable triangular frame, made from timber,
and attached to the flat with pin hinges. Often swung flush to the flat for
storage or flying.
BRACE WEIGHT : Slotted cast iron weight placed on foot of extendible or
French brace to prevent movement. Often referred to as a "Stage
BRAIL : A rope, wire or chain attached at either end of a piece of scenery or
lighting bar pulling it upstage or downstage of its naturally hanging position
to allow another flying item to pass, or to improve its position. See also
BREAK A LEG :
BREAKAWAY : Prop or item of furniture designed to break/shatter with impact.
Breakaway furniture and some props are usuallycapable of restoration to be
BREAST LINE : A form or brail horizontally across the width of the stage,
passed across the fly bars suspension lines and attached at the fly floors to
brail the scenery up or down stage.
BRIDGE : A walkway, giving access to technical and service areas above the
stage or auditorium, or linking fly-floors.
BRIDGE LIFT : An elevator which raises and lowers sections of the stage
floor, usually by electrical or hydraulic means.
BRIDLE : Two or more wires, ropes or chains attached by a ring, eye or
shackle to the end of a grid line and fitted at distances apart with clips to a
barrel or batten and thus distributing the load.
BSI : British Standards Institute.
BUBBLE : (especially TV and Film) Replacement lamp.
1) During lighting plotting, to construct a state from blackout, or to add to
an existing state.
2) An increase in light or sound level. See Check.
3) A period of set construction ("The Build")
BUMP : A flash or sudden jump in light level (a snap cue) (see Flash Button).
BURNT OUT : A coloured gel that has lost its colour or melted through due to
excessive heat in front of a lantern. Dark blues and greens etc. are most
susceptible, and may need replacing during a long run.
BUSS : A signal line within a sound mixing desk that can receive its signal
from a number of sources. eg the Aux 1 buss carries the signals from the input
channels to the Aux 1 Send master control.
CABLE : Wiring, temporarily rigged, to carry electrical current. Depending on
the size of the cable (current carrying capacity), cables are used to supply
individual lanterns, whole dimmer racks, or carry signals from a microphone etc.
CABLE GRIP : A U-shaped clip and saddle used for terminating wire rope. Also
known as a Bulldog or Dog Grip.
CABLE TIE : Lockable (and sometimes releasable) plastic strap used to tie a
bundle of cables together, amongst many other things.
CAD : Computer-Aided Design.
1) A notification of a working session (eg a Rehearsal Call)
2) The period of time to which the above call refers. (eg "Your call for
tomorrow nights show is 6.55pm")
3) A request for an actor to come to the stage because an entrance is
imminent (these are courtesy calls and should not be relied on by actors - eg
"This is your call for the finale Mr Smith and Miss Jones")
4) An acknowledgement of applause (eg Curtain Call)
5) The DSM on the book is said to be "calling the cues".
CANS : Headset earpiece and microphone used for communication and
co-ordination of technical departments during a performance. Also generally used
CANVAS : Used to cover flats as a less heavy alternative to plywood.
CARDIOD : See Pick-up.
CAROUSEL : Circular slide magazine; also refers to a 35mm slide projector
using this type of magazine (Kodak trade name). See Projection.
CARPET CUT : A narrow concealed slot along the front of the proscenium stage
for clamping the downstage edge of a floorcloth. Becoming obsolete, although the
phrase is still used for the setting line.
CARTRIDGE : A tape loop in a box which can cue itself up to the beginning of
the recorded track in a cartridge player. Used extensively for radio jingles,
and sometimes for theatre sound effects.
CASSETTE : Originally, Compact Cassette. Popular domestic 1/8" tape
format. Difficult to cue up accurately, so awkward for live theatre, but cheap,
so often used by small scale touring companies as sound effects source. A
different cassette is used for each effect. Still popular in four track music
CASTING : The process of the director choosing actors to perform the
characters in the play.
CASUALS : Part-time temporary technicians (paid by the hour).
CATWALK : An access walkway to equipment. Unlike a Bridge, not necessarily
across a void.
C.C.T.V. : Closed Circuit television. A video relay system, used in the
theatre to give a view of the stage to remote technical operators (especially
stage managers). Also used to give musical performers a view of the conductor
(and vice versa) to help in keeping time.
C CLAMP : US equivalent of the Hook Clamp. Requires a spanner to tighten.
CD (Compact Disc) : Digital sound storage medium. Provides a high quality
source of music, sound effects etc. Also used as a playback medium for sound
effects etc by large theatres with long running shows, although CDR (Recordable
CD) is becoming more affordable by the day.
CENTRE LINE : Imaginary line running down the stage through the exact centre
of the proscenium opening. Marked as CL on stage plans. Normally marked on the
stage floor and used as a reference when marking out or assembling a set.
CHANNEL : A complete control path for signals in lighting or sound equipment.
CHASE : A repeated sequence of changing lighting states.
CHEAT SHEET : A smaller version of the lighting plan, used by the lighting
designer during the lighting plot.
1) Opposite of Build; a smooth diminishment of light or sound level.
2) See Prefade Listen.
CHIEF ELECTRICIAN : The senior member of the theatre's stage lighting team,
although not necessarily the lighting designer.
CHINAGRAPH PENCIL : Usually white, wax-based pencil used for marking magnetic
tape prior to splicing. Also used for marking identifying numbers of lighting
CID (Compact Iodide Daylight) : A high intensity discharge lamp that produces
a light similar in colour temperature to daylight approx. 5500K). A 1000W CID
lamp produces 2.5 times more light than a 2000W tungsten halogen source.
CIE (Commission Internationale d'Eclairage) : International lighting forum
which has produced a series of universally recognised symbols for lighting
CIRCLE : The balcony with tiered seating above the stalls. Also known as
Dress Circle or Grand Circle.
CIRCLE FRONTS : A permanent front of house lighting position in older
proscenium theatres. A number of spotlights, sometimes fitted with colour
changers, are recessed into the front of the circle balcony above the stalls.
1) The means by which a lantern is connected to a dimmer or patch panel.
Numbered for reference.
2) A complete electrical "loop" around which current can flow.
CITT : Canadian Institute for Theatre Technology.
CIRCUIT BREAKER : An electro-mechanical "fuse" that can be reset,
rather than having to be replaced. Available in the same ratings as fuses. See
CLEANERS : Auditorium working lights. Used for cleaning and setting up the
auditorium before the house lights (usually more atmospheric) are switched on.
CLEARANCE : Message passed to Stage Management from the Front of House
Manager that the house is ready for the performance to begin. (ie everyone is in
their correct seat and there are no coach parties coming through the doors).
CLEARING STICK : A long, often bamboo, rod used to rescue flying objects or
to prevent them from becoming entangled.
CLEAT : Piece of timber or metal for tying off a rope line. Used when flying
or for holding scenic pieces together with a cleat line.
CLEAT LINE : Rope passed through cleats on two adjacent flats alternately to
hold the flats together.
CLEW : A ring of metal which is used to join several flying lines or wires to
a single pulling wire.
CLICKTRACK : Technique for reinforcing the live sound of a musical or band
with recorded sound from one track of a tape. The other track of the tape
consists of a click used by the musical director to keep the live band and cast
synchronised with the recorded band or cast.
CLIPPING : Distortion in a sound signal caused by an amplifier or mixer being
unable to handle the level of signal being fed to it.
CLOTH : A piece of scenic canvas, painted or plain, that is flown or fixed to
hang in a vertical position. A Backcloth hangs at the rear of a scene. A
Floorcloth is a painted canvas sheet placed on the stage floor to mark out the
acting area, or to achieve a particular effect. A Frontcloth hangs well
downstage, often to hide a scene change taking place behind. Cut cloths have
cut-away open areas and are normally used as a series, painted in perspective. A
Star Cloth (usually black) has a large number of small low-voltage lamps sewn or
pinned through it which gives a magical starry sky effect. (See also Fibre
CLOVE HITCH : Invaluable knot that every technician should know.
Many descriptions of how to tie this knot involve complex manoeuvres around a
COLOUR : See Colour Filter.
COLOUR CALL : A list compiled from the lighting plan of all the colours
needed for the rig, and their size. This term also applies to the act of
preparing colour filters and frames from such a listing.
COLOUR CHANGER :
1) Scroller, where a long string of up to 16 colours is passed horizontally
in front of a lantern. Remotely controlled by the lighting desk.
2) Wheel : Electrically or manually operated disc which is fitted to the
front of a lantern with several apertures holding different colour filters which
can be selected to enable colour changes. Can also be selected to run
3) Semaphore, where framed colours are electrically lowered into place in
front of the lantern. Remotely controllable. Can perform additive colour mixing
by lowering two colours into position at the same time.
4) Magazine : Manual semaphore-type device used on the front of a followspot.
COLOUR CORRECTION : The use of colour filters to compensate for the different
colour temperatures of different light sources. Important in lighting for TV and
COLOUR FILTER : A sheet of plastic usually composed of a coloured resin
sandwiched between two clear pieces. The coloured filter absorbs all the colours
of light except the colour of the filter itself, which it allows through. For
this reason, denser colours get very hot, and can burn out very quickly.
COLOUR FRAME or Gel Frame : A frame which holds the colour filter in the
guides at the front of a lantern. Many different sizes of frames are needed for
the different lanterns.
COLOUR MIXING : Combining the effects of two or more lighting gels ;
1) Additive : Focusing two differently coloured beams of light onto the same
area (eg Cyc Floods). Combining colours in this way adds the colours together,
eventually arriving at white. The three primary colours additively mix to form
white, as do the complementary colours.
2) Subtractive : Placing two different gels in front of the same lantern.
Subtractive mixing is used to obtain a colour effect that is not available from
stock or from manufacturers. Because the ranges of colour are so wide, the need
for subtractive mixing is reducing. Combining colours in this way reduces the
light towards blackness. The three primary colours mix subtractively to form
black (or to block all the light).
COLOUR TEMPERATURE :
A measure of the warmth or coolness of light sources and colours. Measured in
degrees Kelvin. The human brain automatically compensates for different colour
temperatures - a film or video camera cannot, and thus what we see as white may
appear to have a blue or green tint when no colour correction is used for video.
Daylight is approximately 5600K and Tungsten Halogen is approx. 3200K.
COMPANDER : Outboard sound equipment. Combination of a Compressor and an
COMPANY : The cast, crew and other staff associated with a show.
COMPLEMENTARY COLOURS : Pairs of colours which, when additively mixed,
combine to produce white light. Examples are red + cyan, green + magenta, and
yellow + blue.
COMPOSITE GOBO : See Gobo.
COMPRESSOR : A piece of sound processing equipment that ensures all wanted
signals are suitably placed between the noise and distortion levels of the
recording medium. It evens out the unwanted changes in volume you get with
close-miking, and in doing so, adds punch to the sound mix. A Limiter is used to
stop a signal from exceeding a preset limit. Beyond this limit, the signal level
will not increase, no matter how loud the input becomes. A Limiter is often used
to protect speaker systems (and human ears) by preventing a system from becoming
CONDENSER LENS : Loosely applied to any spotlight lens which condenses
diverging rays into a beam, but more correctly to the short focus combination of
two or more lenses in a jacket used for illuminating a slide or effect disc.
Also used in some profile lanterns and followspots to produce a smoother light
(especially for gobo work).
CONDENSER MIC (Capacitor Mic) : A microphone that uses the varying
capacitance between two plates with a voltage applied across them to convert
sound to electrical pulses. Condenser microphones need a power supply to provide
the voltage across the plates, which may be provided by a battery within the
case of the microphone, or it may be provided from an external phantom power
supply. A condenser mic is more sensitive and has a faster reaction to
percussive sounds than a Dynamic mic and produces a more even response. See
CONDUIT : Metal or plastic pipe used to carry electrical conductors as part
of a permanent electrical installation. Also used to add weight to the bottom of
a flown cloth.
CONTACT MIC : A microphone that directly picks up the sound transmitted by a
solid material. See Boundary Mic, PCC, PZM.
COOKIE : See Gobo.
CORNER PLATE : A triangle of plywood used to strengthen the corners of a
COUNTERWEIGHT : A standard weight (60 or 30 lb.) used in a counterweight
COUNTERWEIGHT SYSTEM : Method of flying scenery which uses a cradle
containing weights to counterbalance the weight of flown scenery. See Double
Purchase, Single Purchase, Flying.
CRACKED OIL : A smoke effect which creates a haze in the air to make light
beams visible. This effect is rarely used now, because it has been found to be
carcinogenic. See Water Cracker.
CRADLE : Metal frame in which counterweights are carried in a flying system.
CROSS FADE : Bringing another lighting state up to completely replace the
current lighting state. Also applies to sound effects / music. Sometimes
abbreviated to Xfade or XF.
1) A route leading from one side of the stage to the other, out of the
2) An electronic filter in a sound system that routes sound of the correct
frequency to the correct part of the speaker system. Different speakers handle
high frequencies (tweeters) and low frequencies (woofers). Sometimes known as a
An active crossover splits the signal from the mixing desk into high, mid and
low frequencies which are then sent to three separate amplifiers.
CSI (Compact Source Iodide) : A high intensity discharge lamp. Most often
used in followspots, because it has a colour temperature (approx. 4000K) close
to that of the tungsten halogen lamps.
CSM : Company Stage Manager
CUE : The command given to technical departments to carry out a particular
operation. E.g. Fly Cue or Sound Cue. Normally given by stage management, but
may be taken directly from the action (i.e. a Visual Cue).
CUEING : There is a standard sequence for giving verbal cues :
"Stand-by Sound Cue 19" (Stand-by first)
"Sound Cue 19 Go" (Go last).
CUE LIGHT : System for giving technical staff silent cues by light. Red light
means stand-by or warn, green light means go.
Ensures greater precision when visibility or audibility of actors is limited.
Sometimes used for cueing actors onto the set.
For technical cues, lights are normally now used just as a backup to cues
given over the headset system.
CUE TO CUE ("Topping and Tailing") : Cutting out action and
dialogue between cues during a technical rehearsal, to save time.
CUT CLOTH :See Cloth.
CUT-OUT : See Profile
CYC FLOOD : A floodlight, usually with an asymmetrical reflector, designed to
light a cyc or backcloth from the top or bottom.
CYCLORAMA (usually just "cyc") : Plain cloth or plastered wall
filling the rear of the stage. The term is often loosely applied to a blue
skycloth, or any flattage at the rear of the stage. Maybe curved at the ends. A
more effective backing can be obtained by hanging a sharkstooth gauze just in
front of the plain white cyc which gives a hazy effect of distance.
DAISY-CHAINING : Connecting items of equipment together by linking from one
to the next in a chain. Used for connecting demux boxes to dimmers etc.
DAT (Digital Audio Tape) : See Digital Recording.
DARK : A venue that has been closed to the public. Some theatres go dark
temporarily during production periods, when the next show is in preparation on
DAYMAN : A member of the backstage staff whose employment includes work done
DBO (Dead Blackout) : See Blackout.
DBX : A noise reduction process.
DCC (Digital Compact Cassette) : See Digital Recording.
1) A pre-plotted height for a piece of scenery or lighting bar - "that
bar's on its dead". Sometimes flying pieces are given a number of extra
deads, that may be colour coded, in addition to the "in dead" (lower)
and "out dead" (higher - out of view).
2) Scenery or equipment not needed for current production - "that
3) An electric circuit that has been switched off or has failed.
DEAD HINGE : A hinge used as a right-angle bracket.
DEAD ROOM : A room with very thick sound absorbers, causing a very dull sound
with no reverberation.
DECIBEL (dB) : Relative measurement for the volume (loudness) of sound. Also
used to measure the difference between two voltages, or two currents. See Zero
1) Stage/Rostrum Floor
2) Tape deck/Record deck.
DELAY : Outboard sound equipment that can momentarily stores a signal being
sent to part of a P.A. system so that delayed reinforced sound reaches the
audience at the same time as live sound from the stage.
DEMUX BOX : Interface unit between the serial digital output of a memory
lighting control desk to the parallel analogue signal understood by a dimmer.
DE-RIG : The process of removing lanterns & cabling from flying bars or
grid - returning the venue to it's normal state, or as preparation for the next
DESIGNERS CONTROL : See Riggers Control.
DI BOX : Interface unit to convert the high impedance unbalanced output of an
instrument (e.g. Electric guitar) into a low impedance balanced signal of low
level suitable for connection to the microphone input of a mixing desk.
Usually has an output jack socket so that the instruments unprocessed signal
can be passed direct to the musicians amplifier. DI = Direct Injection.
1) See iris.
2) The part of a microphone which responds to sound waves.
DICHROIC FILTER : Glass colour filters which reflect all light except that
which is the colour of the filter, which passes through. Normal gels absorb the
unwanted colours, turning the light into heat. Dichroic filters run cooler, and
produce a much cooler beam of light. Longer lasting, but a lot more expensive.
DICHROIC LAMP : A low voltage display lamp with a reflector that lets heat
pass through it, rather than reflecting it. Results in a much "cooler"
DIFFUSION : See Frost.
DIGITAL : Many electronic devices use digital logic. Information is handled
in separate bits (either ON or OFF) rather than continuously variable analogue
signals. Most computer lighting boards give a digital multiplexed output, and
more and more sound equipment is going digital.
DIGITAL DIMMER : The new generation of dimmers that can respond directly to
the digital multiplexed output of the lighting desk. The technology also permits
the dimmer to report faults and other data back to the control board.
DIGITAL EFFECTS : Reverb, Delay, Phasing, Flanging, Harmonising, Chorusing.
More information coming soon !
DIGITAL RECORDING :
1) ADAM : (Akai Digital Audio Multitrack). 12 track recording onto Video 8
tape. 16 bit, 44.1 or 48kHz sampling rate.
2) DAT (Digital Audio Tape) Cassette-like system which has much higher
quality than standard audio cassettes. Widely used in gathering sound effects,
for news gathering, and for playback of music.
3) DCC (Digital Compact Cassette) Rival to DAT which also plays standard
4) Mini Disk : Uses computer disk technology, rather than tape. A laser heats
an area of magnetic disk which is then written to by a magnetic head. When
cooled, the magnetic information is read from the disk by laser. Tracks can be
named, and are instant start. Very theatre-friendly system.
5) Direct to Disk : Uses the hard disk present in most PCs as the recording
DIMMER : Electrical or electronic device which controls the amount of
electricity passed to a lantern, and therefore the intensity of the lamp.
DIMMER RACK : A number of individual dimmer circuits mounted in a cabinet.
DIN : Deutscher Industrie Normen. European standard covering audio connectors
and tape equalisation characteristics.
1) Small covered trap at stage level containing electrical outlets.
2) Lighting equipment on stands at stage level.
3) Low lighting intensity when cross fading between two higher states.
4) Transparent lacquer for colouring lamp bulbs.
DISCHARGE LAMP : A high-powered source of light produced by means of a
discharge between two electrodes. An arc light, for example uses a discharge
between two carbon rods which are manually or automatically fed together as they
are burnt up. The use of this type of lighting is restricted to non-dimming
applications such as followspots and projection, where dimming is achieved by
mechanical means. Many of the new generation of moving lights use discharge
lamps and dichroic filters. See Ballast, CSI, CID, MSR, HMI, HTI, Xenon, MBI.
DISSOLVE UNIT : Interface connected between two or more slide projectors and
a tape player. Synchronisation signals recorded onto the tape are detected by
the dissolve unit and fade up the lamp in one slide projector while changing the
slide in the other, and then vice versa, producing a dipless crossfade between
the two images.
DISTORTION : Usually undesirable result of overloading sound equipment.
Reducing the levels can remedy the situation.
DISTRIBUTION BOARD : System of interconnected fuse carriers and cabling that
routes an incoming power supply to a number of different outputs.
DIVERSITY : A way of maximising the quality of received radio signal by using
two receivers and aerials tuned to the same frequency - the circuitry
automatically silently switches to the strongest signal.
DMX512 : See Multiplex.
DOCK : See Scene Dock.
DOLBY : Trade name for a series of noise reduction systems that have become
standard on many tape playback machines. Many film soundtracks are produced
using this process. Different varieties are found from Dolby B on most personal
cassette players, to Dolby SR and Digital, the current state of the art for
DOLLY : A small wheeled platform used to move heavy items. (E.g. a piano
DONUT : A metal plate with a hole in the middle inserted in the colour
runners of a lantern to sharpen focus (in the case of a profile) or reduce
DOOR SLAM : A small wooden box with a heavy door and various bolts and locks
used to simulate slamming and other door sound effects offstage.
DOUBLE PURCHASE : Counterweighted flying system where the cradle travels half
the distance of the fly bar, leaving the side wall of the stage under the fly
floors clear of flying equipment. The cradle of a double purchase system needs
twice as many counterweights as that of a single purchase system balancing the
DOWNLIGHT : A light from directly above the acting area.
1) The part of the stage nearest to the audience (the lowest part of a raked
2) A movement towards the audience (in a proscenium theatre).
DOWSER : A metal flag used in larger followspots and projection equipment to
cut off the light beam without cutting off the electrical supply. Discharge
lamps need a period of cooling down when they are turned off before they can be
turned on again, so they should not be switched off if needed again within about
DRAPES : Stage Curtains. See also tabs.
DRENCHER : System of pipes arranged at the top of a safety curtain to drench
it with water in the event of fire.
DRESS CIRCLE : See Circle.
DRESSER : Helps actors with costume care and costume changes during the
DRESSING (the set) : Decorative props (some practical) and furnishings added
to a stage setting. See also Tab Dressing.
DRESS PARADE : Review by director/designer/wardrobe staff of all costumes
worn by cast and paraded under stage lighting. Any defects, misfits etc. are
noted or corrected before the first Dress Rehearsal.
DRESS REHEARSAL : A full rehearsal, with all technical elements brought
together. The performance as it will be "on the night".
DRIFT WIRE : A length of suspension wire of standard length with eyelets at
each end between the counterweight bar and the top of the scenic piece flown
DRUGGET : Canvas or cloth used to mask and/or protect a floor.
1) An actor forgetting the words of his script.
2) To record a sound without using any effect or other processing is to
record it "dry". Recording with an effect is recording
DRY ICE : Frozen solid carbon dioxide (CO2) at a temperature of -87.5 degrees
centigrade which produces clouds of steam-loaded CO2 gas forming a low-lying
mist or fog when dropped into boiling water. Although non-toxic, caution is
required in the storage and handling of dry ice because of its extreme cold.
Water is boiled in a large tank offstage, into which the dry ice is lowered in a
basket. Fans and ducts then direct the gas onto the stage. Dry ice does not
support life, so care should be taken that small animals, actors etc. are not
below the level of the dry ice for more than a few seconds.
DSM : Deputy Stage Manager.
DUBBING : The process of copying a sound from one medium to another (eg onto
videotape) or for backup purposes, simply copying sound tapes.
DUTCHMAN : Tape or material used to cover the seams between flats, prior to
DYNAMIC MIC : Robust type of microphone which picks up the sound on a
diaphragm connected to a coil of wire which moves within a magnet. An
alternating current is induced into the wire which provides the electrical
output. Most dynamic mics have low output impedances of 200 Ohms. See Condenser
EARTHING : Electrical safety requirement that metal parts of electrical
equipment are connected to a common earth or ground point so that in the event
of a fault, excess current can be carried away, causing the fuse to blow. Known
in the USA as Ground.
EARTH LOOP :
EARTH SPIKE : Copper rod inserted into the ground to maintain earth
continuity (especially when using generators etc.)
ECHO : A repeated sound received late enough to be heard as distinct from the
source. See Reverb.
EFFECTS, LIGHTING :
Animation Disc : A slotted or perforated metal disc which rotates in front of
a lantern to provide "movement" in the light. Most effective when used
in front of a profile carrying a gobo.
Effect Disc : A painted glass disc rotating in front of an effects projector
with an objective lens to focus the image (eg Flames, Rain, Snow).
Flicker Flame : Irregularly slotted rotating metal disc through which light
is shone onto a prism-type piece of glass which scatters the beam of light and
adds the "dancing" effect of firelight to a scene.
Gobo Rotators : Motorised device inserted into the gate of a profile lantern
that can be remotely controlled to rotate a gobo, usually with variable speed
KK Wheel : Slotted metal disc which rotates in front of a lantern to break up
the light and provide movement. (Flicker Wheel)
Lightning : Created through the use of either strobe sources or photoflood
Tubular Wave Ripple : Horizontal linear lamp around which a slotted cylinder
is rotated providing a rising light (as reflected from water onto the side of a
See also Effects,Sound, pyrotechnics, smoke.
EFFECTS PROJECTOR : Lantern used to project the image from a rotating glass
effects disc. Used with an objective lens to produce the desired size of image.
Commonly used discs are clouds, flames and rain.
EFFECTS, SOUND :
1) Recorded : Often abbreviated to FX. There are many sources for recorded
sound effects, most recently on Compact Disc. May form an obvious part of the
action (train arriving at station) or may be in the background throughout a
scene (e.g. birds chirping).
2) Live : Gunshots, door slams, and offstage voices (amongst many others) are
most effective when done live. See Door slam, Thunder Sheet, Rain box.
See also Compressor, Digital Effects, Exciter, Noise Gate, Reverb.
ELECTRET MIC : A condenser microphone where the capacitor plates are given a
charge during manufacture which they retain, therefore requiring no external
ELECTRICS : See LX.
ELEVATION : A working drawing usually drawn to scale, showing the side view
of a set or lighting rig. See plan.
ELEVATOR STAGE : A type of mechanised stage which has sections that can be
raised or lowered.
ELLIPSOIDAL : A profile lantern with an elliptical reflector.
ENHANCER : Sound processing equipment which increases the presence of the
vocal track in a mix by adding to the treble information in the signal. Also
known as an Exciter.
ENTR'ACTE : An "overture" to begin the second part or act of a
performance. Often used now to describe any interval music.
EQUALISATION : The process of adjusting the tonal quality of a sound. A
graphic equaliser provides adjustment for a wide range of frequency bands, and
is normally inserted in the signal path after the mixing desk, before the
amplifier. See Feedback.
EQUITY : Short for British Actors' Equity. The trade union of actors,
directors, designers and stage managers.
ESTA : Entertainment Services and Technology Association.
EXCITER : See Enhancer.
EXIT SIGN : Usually illuminated sign, of standard size, which should always
be visible, showing an audience member and the company the nearest exit.
EXPANDER : See Noise Gate.
FADER : A vertical slider which is used to remotely set the level of a
lighting or sound channel. A fade is an increase, diminishment or change in
lighting or sound level.
FALSE PROSCENIUM : A frame formed by scenic canvas or vertical flattage
within the proscenium arch. Used to reduce the size of the opening when
putting a small set onto a large stage.
FALSE STAGE : A special stage floor laid for a production. For example to
allow trucks guided by tracks cut into this false floor, to be moved by steel
wires running in the shallow (2 or 3 inch) void between the false floor and
the original stage floor. A false stage is also required for putting a revolve
onto a stage.
FEED : A power supply to a piece of equipment or installation is termed a
"feed". Sound equipment and sensitive computer equipment should have
a clean feed - that is, a supply that is free from interference from other
FEEDBACK / HOWLROUND : A loud whistle or rumble heard emanating from a
sound system. It is caused by a sound being amplified many times. (E.g. a
sound is picked up by a microphone and amplified through the speaker. The
microphone picks up this amplified sound and it is sent through the system
again). Feedback can be avoided by careful microphone positioning, and can be
reduced by use of Equalisation to reduce the level of the frequency band
causing the feedback.
1) See Swag
2) Describes tabs which adopt a sculpted shape.
3) A length of cable incorporating a number of lamp holders used for
outdoor party lighting etc. Available in multi-circuit form so that the lamps
can be "chased".
FEV : Short for French Enamel Varnish, a stain which is a mixture of
shellac and dye, diluted in methylated spirit.
FIBRE FRAME : A gel frame made from heat resistant fibres, which doesn't
get as hot to the touch as a standard metal frame.
FIBRE OPTIC : A method of directing light down a very thin glass fibre.
Fibre Optics are used mostly in communication, but find theatre applications
in star cloths which are black backcloths with the ends of optical fibres
poked through, to create a mass of pin pricks of light. A large bundle or
harness of fibres may be fed from one light source, sometimes with a motorised
colour or flicker wheel.
FIELD :Refers to the spread of light intensity across a beam. Most profile
lanterns have an adjustable field. A Flat field has an even distribution, a
peak field has a "hot spot" in the centre of the beam. A flat field
is essential when using gobos. See Profile.
FILL LIGHT : (especially TV and Film lighting) Light which fills the
shadows that key light creates.
1) See Colour.
2) Electronic device to isolate and redirect specific frequencies in a
FIRE CURTAIN : See Safety Curtain.
FIRE EXIT : Particular exit(s) from a building designated by local
authority fire officer to be the correct means of escape from a part of the
building in case of fire. It is the responsibility of all staff and performers
to ensure that all fire exits are kept clear, unlocked and accessible at all
FIRE EXTINGUISHER : Carbon Dioxide (Black), Water (Red), Foam (Cream),
Halon Gas (Green) Powder (Blue) .
FIRE PROOFING : Treatment given to fabric, timber, drapes etc. to retard
flammability. Many scenic materials require regular re-application of fire
FIT-UP : Initial assembly on stage of a production's hardware, including
hanging scenery, building trucks etc.
FLASH BOX : A small box containing the socket into which a pyro cartridge
is plugged. Also known as a flash pod.
FLASH OUT / THROUGH : Method of checking whether lanterns are functioning
properly by flashing them on one at a time. It is good practice to flash
lanterns to 70%, rather than Full to preserve lamp life.
FLAT : A lightweight timber frame covered with scenic canvas. Now usually
covered with plywood or hardboard and consequently not so lightweight. Most
theatres have a range of stack flattage made to a standard size, and re-used
many times. A Rail is a horizontal batten within a flat. A Stile is a side or
vertical piece within a flat. A Sill is the bottom rail of a flat. See also
FLIES : See Fly Tower.
FLOATS : Early form of footlights using burning wicks floating in oil
across the front of the stage. Now applies to anything rigged on the front
edge of the stage (eg Float microphones, Uplights etc).
FLOGGER : Strips of canvas attached to a handle for dusting flats or scenic
pieces prior to painting.
1) A lensless lantern that produces a broad non-variable spread of light.
Floods are used in battens, or singly to light cycloramas or large areas of
2) To increase the beam size of a focus spot by moving the lamp and
reflector towards the lens. "Flood that a bit, please !"
FLOORCLOTH : See Cloth.
FLOOR PLAN : See Plan.
FLUORESCENCE : The property of some materials to glow when subjected to
Ultra-violet light. The materials degrade the UV wavelengths into longer and
therefore visible reflected rays. See also Phosphorescence.
FLY BARS : The metal bars to which scenery and lanterns are attached for
flying above the stage.
FLY FLOOR(S) : High working platform at the side(s) of the stage from which
the flying lines are handled. Often are also the site for socket panels for
connecting flown lighting apparatus to dimmers, and also sometimes a lighting
FLYING : See Hemp Set, Counterweight System.
FLY TOWER : Extension of the stage walls up to allow scenery to be flown up
until it is out of sight of the audience. Known as the "flies". The
ideal fly tower should be more than twice the height of the pros. arch, and is
said to have "full flying height".
FOCUS : The session when all the lanterns in the rig are angled in the
correct direction, with the correct beam size.
FOCUSING : The process of adjusting the direction and beam size of
lanterns. Does not necessarily result in a "sharply focused" image.
FOCUS SPOT : Term for both Fresnel and PC type lanterns with adjustable
FOH : See Front of House.
FOLDBACK : Means by which musicians can part of the rest of the sound mix
(including voices) and how their instruments sound after being amplified. Also
enables actors on stage to hear musicians or effects when they cannot hear the
output of the auditorium sound system.
FOLLOW-ON CUE : A cue that is timed to follow an original cue so quickly
that it does not need a separate cue number. Often abbreviated to f/o.
FOLLOW SPOT : Usually, a powerful profile lantern usually fitted with its
own dimmer, iris, colour magazine and shutters mounted in or above the
auditorium, used with an operator so that the light beam can be moved around
the stage to follow an actor. Sometimes a beam light or other lantern may be
used in the same way. See limes.
FOOTLIGHTS : A compartmentalised batten sometimes recessed into the front
edge of the stage, used to neutralise shadows cast by overhead lighting.
Modern lighting equipment renders footlights virtually obsolete except for
FORESTAGE : That part of the stage which projects from the proscenium into
the auditorium. See Forestage.
FRENCH BRACE : See Brace .
FRENCH FLAT : A scenic flat which is flown into position, usually with
FREQUENCY : (measured in Hertz - Hz - cycles per second) The number of
times a sound source vibrates each second. A high frequency (HF) sound has a
higher pitch and is uni-directional. A low frequency (LF) sound has a lower
pitch and is omnidirectional.
FRESNEL :(pronounced "Fre-nell") A type of lantern which produces
an even, soft-edged beam of light through a Fresnel lens. The lens is a series
of stepped concentric circles on the front and pebbled on the back and is
named after its French inventor, Augustin Jean Fresnel (1788-1827).
FRONT CLOTH : A cloth flown well downstage in front of which short scenes
are played while big scene changes are "silently" carried out
upstage. (Common in musicals and pantomime).
FRONT OF HOUSE (FOH) :
1) Every part of the theatre in front of the pros arch. Includes foyer
areas open to the general public.
2) All lanterns which are on the audience side of the proscenium and are
focussed towards the stage.
FRONT OF HOUSE CALLS : Announcements made by stage management or FOH staff
calling the audience into the auditorium, or informing them when the
performance begins. Calls are normally made at the Half (35 mins. before
curtain up), the Quarter (20 mins before), the Five (10 mins), and calls
normally accompanied by bar bells at 3, 2 and 1 minutes before the performance
FRONT TABS : House curtains.
FROST : A diffusing filter used to soften the edges of a light beam.
Different strengths of diffuser are available from many colour filter
manufacturers. See silk.
FULLERS EARTH : Hydrous aluminium silicate, used in chemistry as a filter
and as a binder when mixing powder paint for use on
FULLNESS : Draperies made up with deep "gatherings" have fullness
- usually requiring not less than 50% additional fabric, measured at head and
FUSE : Protective device for electrical equipment (E.g. dimmers). The fuse
link will melt when excess current flows, preventing damage to people or
equipment. Every piece of electrical equipment has at least one fuse in its
FUZZ LIGHT : A lamp with a revolving mirror and a coloured plastic dome.
Gives a "police light" effect. Usually 12 Volt or 240 Volt
FX : See Sound Effect.
Also refers to the floor-mounted block on a bi-parting curtain track
GAFFA TAPE : Ubiquitous sticky cloth tape. Most common widths are .5"
for marking out areas and 2" (usually black) for everything else. Used
for temporarily securing almost anything. Should not be used on coiled cables
or equipment. See PVC Tape.
1) The level of amplification given to a signal or of a system.
2) A control of the amount of pre-amplification given to a sound signal on
its way into a mixer.
1) The point of focus in a profile spot where the shutters are positioned
and where an iris or gobo can be inserted.
2) A single base section of a folding rostrum system.
3) See Noise Gate.
GAUZE : Cloth with a relatively coarse weave. Used unpainted to diffuse a
scene played behind it. When painted, a gauze is opaque when lit obliquely
from the front and becomes transparent when the scene behind it is lit . Many
different types of gauze are available ; Sharkstooth gauze is the most
effective for transformations, because it is the most opaque. Vision gauze is
used for diffusing a scene and for supporting cut cloths.
G-CLAMP : Ironmongery fitting for clamping two items into position
together. See also Hook Clamp.
GEL or Gelatine : See Colour Filter.
GENERAL COVER : Those lanterns in a rig which are set aside purely to light
the acting areas. The stage is normally split into a number of areas for this
purpose, which can then be isolated or blended together as required by the
director. See Special.
GERB : See pyro.
GET-IN : The process of moving set, props and other hardware into a theatre
prior to the fit-up. (aka Load in or Bump in)
GET-OFFS : A means for an actor to get off a rostrum, high level etc. out
of view of the audience. Usually treads.
GET-OUT : Moving an entire production out of the venue, and into either a
large waste-disposal skip, or into transport. Usually preceded by the strike.
(aka Load out or Bump out.)
GHOSTLIGHT : A light left burning overnight on stage to keep friendly
spirits illuminated and unfriendly spirits at bay. Also believed to keep the
theatrical muse in a "dark" theatre.
GLASS FIBRE : A combination of a glass mat and a resin which can be formed
into a strong shell. Used in prop-making.
GLAZE : Glossy finish applied as a final coat to a painted stage floor
(also available as a Matt / Flat finish).
GLOVES : Used when lifting heavier lanterns.
GLS : General Lighting Service. Lamps designed for general everyday use.
GOBO : A thin metal plate etched to produce a design which can then be
projected by a profile
spotlight (E.g. Foliage, Windows). The image can be used soft focus to add
than a defined image.
A number of composite gobos in different coloured lanterns can, with
produce a coloured image (e.g. a stained glass window).
Greater detail can be achieved using a glass gobo.
The original use of the word GOBO came from the early days of Hollywood.
When the Director
of Photography wanted daylight excluded from some area of the set, he'd say
Loads of people would run around putting black material between the sun and
It eventually evolved into other stuff that goes in front of
lights and now most commonlly refering to patterns in Lekos.
In the US TV/Film industry, a Gobo is a piece of material used to mask or
block light and a
Cookie (short for Cucaloris) is the same as a UK Gobo.
GOBO HOLDER : A metal plate designed to hold a gobo of a particular size in
a lantern of a particular type.
GOBO ROTATOR : See Effects.
GODS : Colloquial term for the Upper Circle of the auditorium.
GRAND CIRCLE : See Circle.
GRAND MASTER : See Master.
GRAPHIC EQUALISER : See Equalisation.
GREASEPAINT : Name refers to make up supplied in stick form, for
application to the face or body. Needs special removing cream.
GREEN (obsolete term) : The part of the stage visible to the audience.
GREEN ROOM : Room close to the stage (i.e. the green) for the actors to
meet and relax.
GRELCO : Brand name for a 2 way 5A or 15A electrical splitter. Another name
is Snapper. Sometimes shortened to Grelly.
A three way splitter is known as a Trelly.
1) The support structure close to the top of the fly tower on which the
pulleys of the flying system are supported. Constructed from metal or wooden
2) Arrangement of scaffolding from which lanterns are hung in a performance
space with no flying facilities.
GRIDDED : Any flying piece raised as high as possible into the flys, i.e.to
the limit of travel of the flying lines, is said to have been gridded.
GROUND PLAN : Scaled plan showing the exact position (seen from above) of
all items standing on the stage floor and indicating the position of items
suspended above. Typical scales are 1:24 (.5" to 1 foot) or, metrically
1:25 (1cm to .25m). Venues have a base plan showing proscenium, walls, seating
etc on which individual set and lighting plans can be drawn.
1) A long piece of scenery positioned at the base of a backcloth usually to
mask the very bottom of a cloth or lanterns lighting a cloth.
2) Compartmentalised floodlight battens at floor level used to light the
bottom of skycloths etc.
GROUP : A subdivision, permanent or optional, of a lighting board control
preset, or a sound desk.
GUN MIC : A highly directional condenser microphone.
HALF : Call given to the actors half an hour before they will be called to
the stage for the beginning of a performance. Given 35 minutes before the
advertised time of commencement. Subsequent calls given are the
"quarter" at 20 minutes, "the five" at 10 minutes and
"beginners to the stage" at 5 minutes before curtain up. See also
Front of House Calls.
HALOGEN CYCLE : Chemical process occurring in Tungsten Halogen lamps which
makes them possible. During the lamps life, Tungsten evaporates from the
filament, and would normally deposit itself on the glass wall of a Tungsten
lamp, causing it to blacken, and causing the output of the lamp to reduce
until it finally blew. In a Tungsten Halogen lamp, the Tungsten combines with
the Halogen gas elements present in the lamp envelope and is re-deposited back
onto the filament. This process needs a very high temperature to operate, so
Tungsten Halogen lamps are able to be a lot smaller, and run a lot hotter,
than their Tungsten equivalents. See also Tungsten Halogen.
HANGING IRON : Ironmongery fitting fixed at the bottom of the back of a
flown flat to which the suspension wire is secured.
"HEADS ON STAGE" : A shouted warning (often just "Heads
!") for staff to be aware of activity above them. Also used when an
object is being dropped from above.
1) General term for theatre communication equipment.
2) A headphone and microphone combination used in such communications
systems with a beltpack.
HEMP : A type of rope used for flying, made from fibres found within the
bark of the cannabis plant.
HEMP SET : The simplest flying system consisting of a series of hemp ropes
threaded through pulleys on the grid, and tied off on the fly floor on a
cleat. The usual arrangement is for three ropes to be attached to a flying
piece, named by their position relative to the fly floor (short, centre and
long). These names are used when levelling the flying piece, and giving it a
dead. The three ropes are pulled or let in together, sometimes requiring more
than one person to operate. A theatre using a hemp flying system is known as a
HINGE : See Pin Hinge, Backflap Hinge.
HMI (Hydragyrum Medium arc-length Iodide) : A mercury-halide discharge lamp
with a colour temperature of 5600K (daylight).
HOOK CLAMP : A clamp with a wing bolt for hanging a lantern on a horizontal
lighting bar. See safety chain and boom arm.
1) The audience (eg "How big is the house tonight ?")
2) The auditorium (eg "The house is now open, please do not cross the
HOUSE LIGHTS : The auditorium lighting which is commonly faded out when the
HOWLROUND : See Feedback.
HYDRAULIC : A system of controlling machinery or moving scenery using oil
or water under pressure to move a piston or "ram". Used in many
large-scale shows to automate scene changes.
HYPER CARDOID : See Pick-Up.
100 VOLT LINE : Way of sending speaker signals over long distances without
losing signal strength. Transformers are used in each speaker cabinet to
convert the signal from 100 Volts to a more usable level.
IEC: International Electrotechnical Commission
IMPEDANCE : A term for the electrical resistance found in a/c circuits.
Affects the ability of a cable to transmit low level (e.g. sound) signals over
a long distance. Measured in Ohms. Speakers are rated according to power
handling capabilities (Watts, W) and impedance (Ohms).
INCANDESCENT : Light source consisting of a metal filament (Tungsten) which
glows white hot when current is passed through. See also Discharge Lamp.
INDEPENDENT : 1) An electrical power supply that is totally separate from
the stage lighting control. Used for testing lanterns prior to connection to
the lighting system and also for powering non-lighting equipment on stage and
working lights. See Non Dim.
2) A channel within the stage lighting control which has been temporarily
switched to become independent from the rest of the channels which remain
under the control of the operator.
INDUCTION LOOP : System which amplifies audio frequency currents (from a
microphone over the stage) around a large loop of cable (around the
auditorium) to generate a magnetic field which can be picked up by a hearing
aid switched to the "T" position.
INFRA RED : Invisible part of the electromagnetic spectrum with a longer
wavelength than visible light. Infra-red remote controls are used for lighting
desks and practicals. An infra-red-sensitive CCTV camera can pick up body heat
activity even in a "blackout".
INHIBIT : A way of taking control of a rogue lantern (or lanterns) at the
lighting desk during the operation of a show and removing them from any
further lighting states, until the inhibit is removed. Can also be used for
removing the front of house lighting from a curtain call state.
1) An additional route into a sound desk.
2) An extra lighting state added into the sequence later. See Point Cue.
INSET : A small scene set inside a larger one.
INTELLIGENT LIGHT : See Moving Light.
INTERNALLY WIRED BAR (IWB) : A Scaffolding bar (aluminium) which has a
number of sockets (usually 15A) positioned along its length, the wiring for
which is contained within the bar. See Six Lamp Bar.
INTERVAL MUSIC : Music played in the foyer and/or auditorium during
intervals. Most usually Vivaldi's Four Seasons.
IRIS : Adjustable aperture which, when placed in the gate of a profile
lantern, varies the size of a beam of light. Originally, iris diaphragm.
IRON : See Safety Curtain.
INTERCOM : Usually refers to microphone/headset communications equipment.
Abbreviated to "comms". Also known as "cans".
JACK : Segmented audio connector. Mono Jacks have two connections - tip and
sleeve, and are unbalanced. Stereo jacks have three connections - tip, ring and
sleeve. B-type jacks (also known as Bantam jacks) were originally designed for
use in telephone exchanges and provide a high quality (and expensive) connection
in jackfields. A-type jacks are cheaper and more common, but more fragile. A
type jacks are available in 2 sizes : quarter inch and eighth inch.
JACKFIELD : An array of jack sockets ("jills"), providing
connections to equipment/outlets etc. A patch panel.
JUMPER : An adaptor from one type of electrical connector to another. For
example, a 13 - 15A jumper has a 13A plug and a 15A socket at either end of a
short cable. Also applicable to sound cables.
KELVIN : See Colour Temperature.
KEY LIGHT : (Esp. TV & Film lighting) The dominant light
source/direction in a lighting state. In a sunny drawing room, the key light
would be through the window, for a naturalistic exterior scene the direction
of the key light could change as the sun progressed across the sky. See Fill
KILL : To switch off (a light/sound effect); to strike/remove (a prop).
KILOWATT : 1 kilowatt (1kW) is equal to 1000 Watts
KVA : Kilo-Volt Amps. Unit of electrical power.
LADDER : Non-climbable structure in the shape of a ladder from which
lanterns can be hung in a vertical "stack".
LAMP : What the un-initiated call a light bulb.
1) General term for unit of lighting equipment including spotlight, flood
etc. Term now being replaced by the internationally recognised "luminaire".
2) Glazed section of roof usually in haystack form over the fly tower that
automatically opens in the case of fire. An updraught is created which
inhibits fire from spreading quickly into the auditorium, and prevents
build-up of smoke at stage level.
LASER : Acronym of Light Amplification by Stimulated Emission of Radiation.
A very high energy beam of light that remains virtually parallel throughout
its length. Visible in the air only when a haze of smoke or dust is
introduced. Great care is required when using lasers as this energy can cause
permanent damage to the retina of the eye.
LAVALIER MICROPHONE : Originally, a mic worn around the neck on a string.
Now applies to a small "tieclip" microphone.
LD : Lighting Designer.
LEADER TAPE : Non-magnetic plastic tape used to begin and end sound tapes
and to separate cues on tape. Clear leader tape is used to activate the
automatic stop on some playback machines. Leader tape is available in a
variety of colours.
LEGS : Drape set as masking piece at the side of the acting area. Usually
set up in pairs across the stage and used in conjunction with borders to frame
the audiences view. Apparently, the origin of the phrase "Break a
Leg", meaning to take an extra encore from the legs after a successful
LEKO : A type of ellipsoidal profile spot, much used in the USA.
LEMO : A small metal multipin connector used for connecting radio
microphone heads into the transmitter pack.
LENS : Optical glass with one or both sides curved, the purpose of which is
to direct light by concentrating or dispersing light beams.
LIBRETTO : Text of opera, or other long musical vocal composition. The
script of a musical.
LIFT : The orchestra pit and/or sections of the stage may be mounted on
lifts to make moving of heavy items (e.g. piano etc.) easier. Sometimes the
forestage doubles as the orchestra pit by use of a lift.
LIGHT CURTAIN : A lighting effect which, when an area is diffused with
smoke, produces a wall of light. Produced (usually) by a batten of low voltage
PAR lamps wired in series. Automated versions are available which have colour
changers built-in and are able to tilt up and down.
LIGHTING PLAN : A scale drawing detailing the exact location of each
lantern used in a production and any other pertinent information (E.g. its
dimmer number, focus position and colour number). Often drawn from the
LIGHTING PLOT : The process of recording information about each lighting
state either onto paper or into the memory of a computerised lighting board
for subsequent playback. (in USA, this term is used for a lighting plan and a
lights session is when lighting states are set up.)
LIGHTING STATE : The format of lighting used at a particular point in the
production; a lighting "picture".
LIGHTING STENCIL : Plastic stencil containing a range of scale symbols for
current lighting equipment. Greatly facilitates the drawing of lighting plans.
LIMELIGHT : An obsolete source of intensely bright light, most recently
used in followspots. See limes. Derived from a burning jet of oxygen and
hydrogen impinging on a rotatable cylinder of lime.
LIMES : Follow spots and their operators. This term is still in everyday
use, although limelight is not.
LIMITER : See Compressor.
LINE LEVEL SIGNAL : "Standard" level at which the inputs and
outputs of domestic and professional sound equipment operate. Slight
variations are that some equipment works at +4dB, some at -10dB. See Mic Level
LINE-UP TONE : Signal of known frequency and level used for setting up
sound recording equipment levels accurately.
LINK : See Point Cue.
LINNEBACH PROJECTOR : Lensless system for projecting a shape from a gel or
glass slide etc. placed in front of a floodlight onto the set. Often used for
1) The electrical power rating, in Watts, of the equipment connected to a
particular lighting dimmer.
2) The equipment connected to a dimmer.
LOAD STRAP : Woven strap with a ratchet tensioner used for securing a load
in a lorry.
LOADING BAY : Access into the theatre for scenery and other equipment. Also
called the Get In.
LOUDSPEAKER : Device for converting the electrical signal from an amplifier
back into sound waves, most commonly by vibrating a paper cone. Most speaker
systems are composed of a number of sources - each designed to handle a
specific range of frequencies. See Tweeters and Woofers, Bi-Amplification.
LOW VOLTAGE : Lower voltage lamps give more intense light than mains
voltage lamps of the same wattage.
LUAN (US) : A flexible 3 ply timber, used for cladding flats etc.
LUMEN : A measure of light output from a source.
LUMINAIRE : The international term for lighting equipment. Not restricted
to theatre lighting.
LUX : A measure of the level of illumination on a surface (1 lumen spread
over 1 metre).
LX : Short for Electrics. The department in the theatre responsible for
stage lighting and sometimes sound and maintenance of the building's
LX TAPE : See PVC tape.
MAHL-STICK : A short stick used by scenic painters to steady the hand by
resting its padded end against the surface being painted.
MAINTAINED LIGHTING : See Secondary lighting.
MANUAL DESK : A lighting desk where the interface between operator and
dimmer is a fader, rather than a computer. Many modern manual desks have some
memory facilities built in, but there are still a large number of venues with
solely manual systems.
MARKING OUT : Sticking tapes to the floor of the rehearsal space to
indicate the groundplan of the scenery. Also for marking position of furniture
etc. within a set.
MAROON : An electrically detonated pyrotechnic device giving the effect of
a loud explosion. Made from gunpowder encased in stout cardboard or string.
Must be used within a metal bomb tank.
MASKING : Neutral material or designed scenery which defines the
performance area and conceals the technical areas. (e.g. Masking flat).
MASKING TAPE : Paper sticky tape used to mark out the boundary of a surface
to be painted or sprayed.
1) An overall control on a lighting or sound control board. The Grand
Master takes precedence over all other controls. See Submaster.
2) An original (e.g. Master tape, master plan) which should be used only to
make a copy from which to work.
MATRIX OUTPUT : Set of outputs on a mixing desk which allows the user to
preset a number of output configurations. eg on a 8 x 8 matrix, each of the 8
group outputs from the channels can be routed to any or all of the matrix
MCB : Minature Circuit Breaker. Up to 63A. See Fuse.
MCCB : Moulded Case Circuit Breaker (over 63A). See Fuse.
1) Musical Director. Often the conductor/leader of a musical, or the person
responsible for the musical content of a production.
2) Mini Disc. See Digital Recording.
MDF : Medium Density Fibreboard.
MEATRACK : Wheeled rack for transporting a number of pre-rigged six-lamp
bars or lanterns.
MEMORY BOARD : An electronic storage device which enables recording and
subsequent "playback" of lighting states.
MIC : (pronounced "Mike") Abbreviation for microphone.
MIC LEVEL SIGNAL :Low level audio signal produced by circuitry in
microphone. Needs boosting either by a pre-amp or a mixing desk before it can
be amplified. Susceptible to interference over long cable runs.
MICROPHONE : Device for converting sound into electrical pulses which can
then be amplified or recorded onto tape. Signals from a microphone are very
low level and are amplified in the mixing desk to line level.
See Dynamic Mic, Condenser Mic, Phantom Power, Pick-up, Radio Mic.
MICROPHONE CAPSULE : An interchangable microphone head that fits onto a
pre-amplifier. Many capsule types are available, all of which fit the same
MIDI : Musical Instrument Digital Interface. Control system for linking
musical instruments or other electronic equipment and computers together and
storing the control signals the equipment produces for subsequent playback.
See MSC and MMC.
MIMIC : The VDU associated with most medium and large lighting desks has a
detailed mimic of the level of all dimmers and other associated information.
MINI DISC : See Digital Recording.
MIRROR BALL : A lighting effect popular in ballrooms and other dance halls.
A large plastic ball covered with small mirror pieces. When a spotlight is
focused onto the ball, specks for light are thrown around the room. Usually
motorised to rotate. [Picture]
MIXDOWN : The process during which a multitrack recording is balanced and
transferred to two tracks (stereo) for playback or reproduction.
MIXER : A desk comprising a number of input channels where each sound
source is provided with its own control channel through which sound signals
are routed into two or more outputs. Many mixing desks can also change the
quality of the sound (see Equalisation). A Powered Mixer has an amplifier
built into it. Sound sources of varying levels are accepted which can be
amplified if necessary. (See Line Level, Gain).
MMC: MIDI Machine Control. A variation of the MIDI language designed for
controlling mechanical equipment (eg Tape Players).
MODEL : A scale model provided by the set designer to help all the
technical departments to co-ordinate and plan a production. Used as a
reference when building, painting, dressing and lighting the set.
1) An onstage speaker which allows a performer to hear the output of the PA
system, or other members of a band.
2) A video display screen
MONKEY POLE : A stick threaded at one end with the line used to cleat two
adjacent flats together, enabling the flats to be quickly and silently joined
or separated. The stick remains attached to the line and flat of which it
MOON BOX : Lighting effect. A large shallow circular box with calico on one
face and low wattage lamps arranged on the back. Can be flown behind a gauze
or thin cyclorama to give the effect of the moon rising.
MSC : MIDI Show Control. A control language which is an extended version of
the original MIDI language. In addition to a "go" command, cue
numbers and other information can be sent as well (in addition to fault
reports and safety checks).
M.S.R. : (Medium Source Rare Earth) High efficiency discharge lamp with a
high colour temperature.
M.U. : Musicians Union.
MULTICORE : A flexible electrical cable composed of several well-insulated
cores covered in a strong PVC or rubber covering. Enables a number of
different circuits to be carried down one piece of cable. Both lighting and
sound multicores are available.
MULTIPLEXED (MUX) SIGNAL : All modern lighting desks use this serial form
of communication with dimmers. All the information from the desk is
transmitted along a single pair of cables to the dimmer where a
de-multiplexing unit (demux box) decodes the string of data and passes the
correct piece of information to the correct dimmer. The inductry standard
protocal (language/standard) for multiplexing is the digital USITT DMX512.
However, new protocols are continually being added to keep up with more
demanding equipment. SMX is a communications protocol which enables digital
dimmers to "report back" to the desk on any faults (eg blown lamps).
D54 uses a stream of analogue voltage levels and was the Strand standard
before DMX512 arrived.
NAB : National American Broadcast. Standard for tape recording equalisation
1) A type of discharge lighting generated by a high voltage across two
electrodes at opposite ends of a long, thin glass tube filled with neon gas.
Different colours can be obtained by mixing other gases, or by using fluorescent
coatings. Mostly used for advertising signs - the glass tube is bent to form
2) A small mains voltage indicator lamp.
NEUTRAL DENSITY FILTER : (ND) Lighting filter which reduces the brightness of
a light source without changing its colour.
NOISE GATE : A piece of sound processing equipment that reduces background
noise by muting a sound signal when it falls below a certain level, restoring it
when the level increases again. Must be used on vocal microphones with care,
because it may cut the signal off, although the vocalist is still singing
quietly. Also known as an Expander.
NON DIMS : Channels, usually controlled from the lighting desk which are
switched, rather than dimmed. This enables motors, slide projectors, smoke
machines etc to be controlled from the lighting desk.
O.P. : Opposite Prompt side of the stage. Stage Right. (ie Actors right
when facing audience).
OFFSTAGE : A movement towards the nearest side of the stage from the
OHM : The unit of electrical resistance.
OISTAT : International Organisation of Theatre Scenographers, Technicians
OMNIDIRECTIONAL : See Pick-up.
ONSTAGE : A movement towards the centre of the stage from the sides.
OPEN THE HOUSE : Clearance given to FOH staff by stage management that the
stage is set and the audience can begin to take their seats. When this
clearance is given, the backstage call "The House is now open, please do
not cross the stage" is made.
OPEN WHITE : (o/w) Lighting with no colour filter.
OUT : In flying, means up (out of sight).
OUTRIGGER : An extendible leg to increase the stability of access equipment
(eg Tallescope, Scaffold tower).
PA SYSTEM : See Public Address System
PAD : A switch on a mixing desk input channel which attenuates (reduces the
level of) a signal.
PAGING : The act of holding a tab etc. back to allow large items or actors
offstage. Also preventing microphone etc cables from getting entangled by
pulling / releasing them from offstage as performer walks around.
PAINT FRAME : Large vertical wooden frame from which cloths are hung for
painting. The frame is often winchable for easy access.
PAIRING : Connecting more than one lantern to one power outlet via an
adaptor or splitter, or more than one speaker to one amplifier channel.
PAPER THE HOUSE : Marketing technique. Giving away tickets to a performance
(eg Opening Night) to make a show seem to be selling better than it actually
PAR : Short for Parabolic Aluminised Reflector lamp. A lamp containing a
filament, reflector and lens in one sealed unit. Used in Parcans to produce a
high intensity narrow beam of light. Par lamps are available in many different
sizes and powers. Par sizes available include 16, 36, 38, 56 and 64. (The
number refers to the diameter of the lens, in eigths of an inch). The most
common for theatre use are Par 64s rated at 1000W (1kW), although other
wattages are available.
PARABOLIC REFLECTOR : See Par.
PARAMETRIC EQ : Equalisation control where the range of frequencies to be
boosted or cut can be selected. Allows the "fine-tuning" of the
PASS DOOR : A fire-resisting door in the wall of the proscenium arch which
is the only correct access between the auditorium and the stage.
PASSIVE : See Active.
1) To cross-connect lighting circuits around the stage area to a chosen
dimmer. Connecting lanterns to dimmers.
2) Using a cross-connect panel which enables any stage lighting channels to
the control desk to control any dimmer or group of dimmers. Some large
lighting boards have the facility for soft patching - a totally electronic way
of patching. Some Rock Desks have a pin patch which allows groups of dimmers
to be allocated to a particular control channel. Also applies to routing of
PATCH PANEL : A board consisting of rows of sockets into which plugs can be
connected to route sound signals or power for lighting circuits.
PATTERN NUMBER : Many older Strand lanterns are identified by their Patt.
number (eg Patt.23 is a 500W profile). The numbers bear no direct relation to
their size or type (although lanterns of a similar design may have similar
PC : Originally short of plano-convex - the basic lans shape of many
lanterns / projectors. Now short for Prism- or Pebble-convex: a type of lens
with a pebbled flat surface which gives a slightly harder edge than a Fresnel,
but not as hard as a Profile. PC refers to a lantern with a PC lens.
PCC : Phase Coherent Cardoid. See Boundary Mic.
PD's (Per Day) : A daily payment by an employer to touring technicians to
cover daily living expenses. This is additional to the monthly / weekly wage.
PEBBLE SPOT : See PC.
PERCENT : Dimmer levels are expressed as a percentage of the supply
voltage. (100% = 240 Volts(UK)).
PERCHES : Lighting positions (often on platforms) at each side of the
stage, immediately behind the proscenium.
PERIAKTOI : Greek term for three-sided flats mounted on a rotating base.
Used in rows to produce easily changed backings.
PERSONAL PROPS : See Props.
PFL : See Pre-Fade Listen.
PHANTOM POWER : Some condenser microphones require a power supply in order
to operate. If this supply is not from a battery within the microphone body,
it is known as a phantom power supply. It is usually 48 Volts DC (can be 9 -
52 volts from most mics), and is supplied either by a separate battery pack,
or by the sound desk. The supply is termed "phantom" because it is
"invisibly" carried down the same microphone cable as the sound
PHASES : Electricity is generated and supplied to large installations in
three phases. Each of the Red, Yellow and Blue phases are supplied down one
cable to the building, but effectively give three separate supplies. Because
there is a potential difference (voltage) of 415 volts between two phases,
care must be taken that pieces of equipment powered by different phases are
not capable of being touched at the same time in case of a fault.
PHONO PLUG : An unbalanced audio connector used for connecting line-level
equipment together (eg CD player, tape recorder). Unsuitable for professional
use due to lack of durability.
PHOSPHORESCENCE : The property of some materials that can store light
energy and glow in the dark.
PHOTOFLOOD : A lamp used by photographers which gives a bright white light.
Because it has a thin filament, it gives a good flash effect (eg lightning),
but has a relatively short life, so should not be left on for any length of
PIANO DRESS : Rehearsal in costume and with all technical facilities but
using a piano as a substitute for orchestra, so that the director can
concentrate on technical problems rather than musical ones (and not pay the
1) Device which, when attached to an acoustic musical instrument, converts
sound vibrations into an electrical signal.
2) A way of describing the directional sensitivity of a microphone. An
Omnidirectional microphone has equal pick-up from all around, a Cardoid
microphone is more sensitive from the front, a Hypercardoid has very strong
directionality from the front. A figure-of eight microphone picks up front and
rear, but rejects sound from the sides.
PIN HINGE : Hinge with removable pin used to join two pieces of scenery
together (ie one half of the hinge is on each piece of scenery).
PINK NOISE : Random sounding audio noise containing all frequencies in the
audio spectrum tuned to the response of the human ear. Used with a Spectrum
Analyser to set equalisation equipment for a large PA installation. However,
the human ear is still a better judge of how a system sounds. See also White
PIN PATCH : See Patching.
PIN SPOT :
1) A lantern focused very tightly on a small area (eg an actors head)
2) A luminaire used widely in disco installations, consisting of a low
voltage Par 36 lamp with a fine beam in a metal case with built in
PIPES : US term for the bars on which scenery and lanterns are flown.
PIT : The area housing the orchestra. Originally, a lower section between
the front of the stage and the audience, although now describes any area
around the stage housing the musicians.
PITCH CONTROL : Facility on some sound playback devices for changing the
speed of playback, and thus the pitch or frequency of the sound, to match an
existing sound, or to fit a particular timeslot. Some Professional CD players
have tempo controls which speed up the playback, and then compensate for the
resulting increase in frequency using a pitch change. This results in the
ability to match the beat of a CD in a disco situation, without the "Pinky
and Perky" effect.
PLAN : A scale drawing showing a piece of scenery, lighting layout etc from
above. Lighting plans are usually drawn onto the theatre's groundplan.
PLASA : Professional Lighting and Sound Association (UK)
PLATE REVERB : Reverb effect produced using a large metal plate. A signal
is supplied to an acoustic transducer at the edge of the plate, causing
vibrations which are picked up by transducers at other locations on the plate.
This type of reverb can be simulated by some digital effects units.
PLAY AS CAST : Contract drawn up for an actor when casting is not complete.
PLAYBACK : The part of a computerised lighting control desk which enables
the operator to recall cues from the electronic memory.
PLOT : List of preparations and actions required of technical crews during
the performance (eg Sound Plot = list of sound cues and levels in running
PLOTTING SESSION : Time during which the plot for each department is
prepared (eg Lighting Plotting session)
PLY : Short for Plywood.
POINT CUE : A cue inserted during / after plotting between two existing
cues. (eg 8.5 is inserted between cues 8 and 9 and cues by the stage manager
as 8A). Most computer lighting desks have the ability to either insert an
additional cue in a sequence, or to link to another cue out of the sequence,
and then link back again. Inserting cues into a plotted sequence on a manual
lighting desk is more awkward, because it is a running plot (where only the
changes between cues are noted down).
POLE OPERATION : A mechanical means whereby pan (horizontal rotation), tilt
(up and down) and focus of a lantern may be adjusted by a pole from floor
level. Commonly used in TV & Film studios where fast resetting of postions
POP SCREEN : A thin gauze screen placed between a singer and a microphone
to reduce vocal "popping" and other breath noise.
POP SHIELD : A foam shield placed over the end of a microphone to reduce
the pick up of vocal "popping" and external wind noise.
PORTAL : An archway made by combining wings/legs and border.
POWER AMPLIFIER : Converts sound signals of line level (approx 1 volt) into
tens of volts, with currents of around 1 Amp to drive speakers.
PPM : (Peak Programme Meter) Meter, often with green/red LED's, giving an
accurate indication of the electrical nature of an audio signal (see also VU).
PRACTICAL : Any object which appears to do onstage the same job it would do
in life, or any working apparatus (eg light switch or tap). An electrified
PRE-FADE LISTEN : Often shortened to PFL. Control on a sound mixing desk
which allows the user to check the presence of a signal, and its quality
before bringing up the fader. Also vital for fault-finding, where the route of
a signal can be PFL'ed around the desk until the point where the fault occurs.
Also known as Check and Cue.
PREFADE / POSTFADE : An output from a sound desk is said to be prefade if
it is independent of the channel fader. If it is postfade, the level of the
output is relative to the channel fader.
PREFOCUS CAP : A type of lamp base which ensures that the filament is
correctly lined up relative to the reflector and lens.
PREHEAT : Smoother lighting builds from zero are achieved when a lamp
filament has been warmed (at approx 15%) in the previous state.
1) Anything in position before the beginning of a scene or act (eg Props
placed on stage before the performance, lighting state on stage as the
audience are entering.)
2) An indepenently controllable section of a manual lighting board which
allows the setting up of a lighting state before it is needed. Each preset has
a master fader which selects the maximum level of dimmers controlled by that
PREVIEW : A function on some memory lighting control desks with video
mimics. Preview enables the operator to see the levels of dimmers and other
information in a lighting state other than that on stage.
PRIMARY COLOURS : The primary additive colours of light are red, green and
blue, and the subtractive colours are cyan, magenta and yellow.
PRODUCTION DESK : Table in the auditorium at which director/designer etc
sit during rehearsals (especially technical rehearsals). Usually has its own
lighting and communications facilities.
PRODUCTION MANAGER : Responsible for technical preparations, including
budgeting and scheduling of productions.
1) Shaped piece of scenery added to the edge of a flat instead of a
straight edge. Also known as a cutout.
2) A type of lantern with at least one plano-convex lens which projects the
outline of any chosen shape placed in its gate, sometimes with a variable
degree of hardness/softness. Profiles include four beam-shaping metal
shutters, a gate to take an iris or gobo and an adjustment to make the beam
smooth and even ("flat") or hot in the centre ("peaky").
See Bifocal Spot, Zoom Profile.
1) Slides are used to project still archive images or textures. Libraries
of slides contain images for every occasion. Kodak Carousel projectors are the
industry standard, and some types can be linked to a controller to perform
complex dissolves and fades from one projector to another. More powerful
projectors are available using very intense discharge sources and large format
glass slides to produce a massive image.
2) Lighting effects : Moving cloud / rain / fire effects can be achieved
using a powerful lantern known as an effects projector with a motorised glass
disc painted with the required effect. An objective lens is required in front
of the disc to focus the image. See Effects.
3) Gobos : See Gobo.
4) Film : 35mm film projection is common in many theatres as a device for
keeping the building open to the public when productions are in preparation.
16mm film projection is used in smaller venues. Film projection can, of
course, also be integrated into a performance.
5) Video : Video projection is now being used to bring television pictures
to the large screen. Cheaper than using film, but the image quality is not as
good. Video projection equipment can also be more difficult to set up.
Images can be front projected or back projected depending on the amount of
space and the effect required. For example, if actors are required to walk in
front of the screen and not have the image appearing on them, back projection
is the only answer. See Screen.
PROMPT BOOK : Master copy of the script or score, containing all the actor
moves and technical cues, used by stage management to control the performance.
Sometimes known as the "book".
PROMPT CORNER : Area, traditionally on the stage left side of the stage,
from which the stage manager (or DSM) controls ("prompts") the
performance, from the prompt desk.
PROMPT DESK : The control centre of the show. The desk should contain most
of the following: a clock, low level lighting, a flat surface for the prompt
script, communication facility to other technical departments, a phone for
emergency, rear and front of house calls system and cue light controls.
PROMPT SIDE (PS) : Usually stage left side of the stage, containing the
PROPPING : The task, usually performed by stage management, of going around
finding / borrowing / buying props for the production.
PROPS : (Properties) Furnishings, set dressings, and all items large and
small which cannot be classified as scenery, electrics or wardrobe. Props
handled by actors are known as handprops, props which are kept in an actors
costume are known as personal props.
PROPS TABLE : Table in convenient offstage area on which properties are
prepared prior to a performance and to which they should be returned after
PROS.ARCH : Short for Proscenium Arch.
PROSCENIUM ARCH : The opening in the wall which stands between stage and
auditorium in some theatres; the picture frame through which the audience sees
the play. The "fourth wall".
PROTOCOL : See Multiplex.
PSU : Power Supply Unit.
PUBLIC ADDRESS SYSTEM : The venue auditorium sound system. Usually
shortened to "PA".
PUBLICITY : The department in the theatre whose job it is to entice the
audience into the theatre, and to tell them what they need to know in order to
get the most from the production.
PUNCH IN : A facility on multitrack recorders which allows you to
"drop in" a sound onto a track whilst playing through the tape,
sometimes controlled by a footswitch. Useful for correcting mistakes in an
already recorded tape.
PUSH AND PULL : Actors who have to move scenery / furniture around the
stage, earning them extra money. Slang term is Pickfords, after the UK
Furniture removals company.
PYROTECHNICS : (Pyro) Chemical explosive or flammable firework effects with
a manual detonation. Usually electrically fired with special designed
fail-safe equipment. Types of pyro range from the Theatrical Flash (a flash
and a cloud of smoke) to the Maroon (which produces a very loud bang). A Gerb
is a version of the Roman Candle firework, throwing a shower of sparks into
the air. All pyrotechnics should be used with close reference to local
licensing laws, and the manufacturers instructions.
PVC TAPE : Plastic insulating tape used for taping cables to bars and for
securing coiled cables. Neater and cheaper than Gaffa tape. Also known as LX
PZM : Pressure Zone Microphone. See Boundary Microphone.
QUADROPHONIC : A sound system which uses four independent speakers (or sets
of speakers). The fore-runner of today's Surround Sound. See Stereophonic.
QUARTZ HALOGEN : See Tungsten Halogen.
QUICK CHANGE ROOM : Area adjacent to the stage containing lighting, a
mirror and a costume rail in which actors can make costume changes quickly,
sometimes with the aid of a dresser.
ROPHONIC : A sound system which us (19") into which various components
can be bolted. Racks are ideal for touring equipment, are neat, and they allow
easy access to the rear and front panels.
RADIO CONTROL : System whereby battery-powered practicals / props on stage
can be controllable from offstage with no connecting leads.
RADIO MIC : Device consisting of a microphone head, transmitter pack with
batteries, aerial and mains receiver unit which allows actors and singers to
be amplified with no visible means of connection. Almost universally used in
musicals where the singers have to be amplified to be heard over the orchestra
/ band. Used in non-musical shows for sound reinforcement.
RAIL : See flat.
RAIN BOX : A box or tray containing dried peas etc which produces a rain
sound effect when inclined.
RAKED STAGE : A sloping stage which is raised at the back (upstage) end.
All theatres used to be built with raked stages as a matter of course. Today,
the stage is often left flat and the auditorium is raked to improve the view
of the stage from all seats. A rake is expressed as a ratio (eg a 1:25 rake
rises by 1cm vertically over 25cm horizontally).
RCD : Residual Current Device. Protects the user against short circuit and
earth leakage caused by damaged cable or faulty equipment. A RCCB (Residual
Current Circuit Breaker) is a combined MCB and RCD, protecting against earth
leakage/short circuit and overload.
REAR OF HOUSE (ROH) : The backstage and storage areas of the theatre.
REPERTOIRE : A form of organisation where two or more productions alternate
in the course of a season.
REPERTORY : A form of organisation, usually with a permanent company of
actors, where each production has a run of limited length. At any time, there
is normally one production in performance, another in rehearsal and several
others in varying degrees of planning.
RE-RIG : To change the lighting rig after the last performance of one show
to the positions for the next show.
RESISTANCE DIMMER : A now obsolete method of dimming which decreases the
current available to the load by introducing a variable resistance between
supply and load. The excess current is converted into heat. Based around a
RETROFIT : A modification that can be made to an existing piece of
equipment after purchase to bring it up to date.
1) A piece of flattage linked and at an angle to another piece of flattage.
2) A financial report given to theatre management staff by the box office
manager on a daily or weekly basis setting out the takings for performances.
3) Route for an auxiliary signal back into a sound mixer.
REVEAL : A return which is at right angles to a flat, and suggests the
thickness of a window, wall, doorway etc.
REVERB : (Reverberation) Effect which may be added to sound effects during
recording or to a voice during performance. Sustains the sound longer than
normal, as if the sound was reverberating around a large building (eg
cathedral). Persistance of sound after the source has ceased.
REVOLVE : A turntable built into the stage floor on which scenery can be
set and then driven into view. Can be electrically chain driven, or manually
pushed into position. A revolve can also be built on top of an existing stage.
REVOX : Brand name of the once industry standard reel to reel tape
recorder. Still enormously popular and universally known.
RF : Radio Frequency
RIAA : Record Industry Association of America. The standard equalisation to
be applied to a signal from a record deck pick-up. Phono pre-amps have RIAA
RIBBON MIC : Delicate mic not suitable for high sound pressure levels.
Consists of a corrugated conductive foil strip suspended between opposing
magnetic poles which is excited by pressure differences between the front and
rear of the microphone and induces a current.
RIDER : (Technical Rider) Information sent to a venue by a touring group
detailing lighting, sound, satging and dressing room requirements. Ideally
arrives before the group !
RIFLE MIC : See Gun Mic.
1) The construction or arrangement of lighting equipment for a particular
production.(noun) 2) Installing lighting, sound equipment and scenery etc for
a particular show.(verb)
RIGGERS CONTROL : A remote control for a lighting desk which enables dimmer
channels to be called up from the stage when rigging or focusing. Usually
battery powered, sometimes with infra-red (cordless) control. A Designers
Control allows whole memories to be called up and/or played back, as well as
Spanset : Woven strap designed to be wrapped around girders and other
structural support points. Has loops at each end to which a shackle carrying a
suspension cable can attach. Available in a number of different loads.
1) The vertical portion of a step which gives a set of treads its height.
2) A microphone which can be raised through a small trap in the stage floor
to a convenient height for an actor. Usually positioned just upstage of the
footlight position, centre stage.
ROAD MANAGER (ROADIE) : A touring technician with one night shows,
particularly music groups. Large groups will have a roadie in charge of a
particular instrument or set of instruments (eg Guitar Roadie, Drum Roadie,
Lager Roadie) who is responsible for the correct unloading and setting up
(tuning etc) of the instruments before the artists arrive onstage for the
ROCK DESK : Lighting control desk designed for rock concerts, the main
feature of which is the ability to group a set of dimmers under the control of
a series of flash buttons, enabling the operator to "play the
lights" in time to the music. These desks usually have a very good
lighting effects capability.
ROH (Rear of House) : The backstage areas of the theatre.
ROLLER : A system whereby cloths can be rolled up/down instead of flying
in/out in a theatre where there is no fly tower, or limited flying height.
ROSTRUM : (plural ROSTRA) A portable platform, usually in the form of a
collapsible hinged framework (Gate) with a separate top (Lid).
RUCHE : (pronounced ROOSH) A pleating or gathering of cloth / drapes.
RUN : A sequence of performances of the same production.
RUNNING PLOT : A plot giving details of the changes between cues, as
distinct from a state plot which gives the whole state of the system at any
time. For example, a lighting plot on a manual board is normally a running
plot. It is difficult to start a running plot half way through; often the
operator has to go back to the beginning and work through until the required
point is reached.
1) A pair of curtains parting in the centre and running horizontally,
particularly those used in a downstage position in variety and revue
2) Persons employed as production assistants to do odd jobs and errands
during a production period.
SAFETY CHAIN : Chain or wire fixed around lantern and lighting bar or boom
to prevent danger in the event of failure of the primary support (eg Hook
Clamp). A requirement of most licensing authorities.
SAFETY CURTAIN : A fireproof curtain that can be dropped downstage of the
tabs to separate the audience from the stage in the event of fire. A Safety
Curtain is required by most licensing authorities for theatres over 500 seats.
The regulations also require that it is raised and lowered at least once in
view of each audience (usually during the interval). Usually made from sheet
metal and electrically operated, used to be made from iron faced with asbestos
and lowered using a hydraulic damping system. Colloquially known as the
"iron". See also Drencher.
SAMPLING : The technique of recording a sound digitally (translating the
analogue audio waveform into a series of electrical ons and offs that can be
manipulated by a computer) for subsequent processing, editing and playback.
SAND BAG : Attached to an unused spot line to stop it running back through
the pulleys, and to enable it to fly in without fouling adjacent equipment.
SATURATION RIG : An arrangement of lanterns in which to maximum number of
spotlights is placed in every possible position.
SBTD : Society of British Theatre Designers.
SCENE DOCK : High-ceilinged storage area adjacent to the stage, sometimes
used for building and storing scenery.
SCENIC PAINT : Traditionally, a mixture of glue size, water and pigment.
Modern practice has also adopted PVA (emulsion glaze) as a bonding medium
which can be used when scenery has got to be washed and used again.
SCENOGRAPHER : Designer responsible for all the visual aspects of a
production (lighting, scenery, costumes etc).
SCREEN (PROJECTION) : Many types of projection screen are available. Some
are multi-purpose, some only for front projection, some only for back
projection. If a screen is not self-supporting, it often has eyelets around
the outside edge which are used to "lace" the screen onto a larger
SCREW EYE : A threaded metal ring screwed to the rear of a flat for
securing a stage brace.
1) A coarse gauze
2) A fine metal mesh used to reduce the intensity of light from TV lanterns
without affecting colour temperature.
SCROLLER : See Colour changer.
SECONDARY LIGHTING: Separately powered lighting system for use throughout
the building in the event of failure of the primary system. Usually battery
powered. Maintained lighting is on all the time, regardless of changes in the
stage lighting, and is battery backed-up.
SEGUE (pronounced "segway") : Musical term for an immediate
follow-on. Often used as jargon for any kind of immediate follow-on.
SEMAPHORE : See Colour Changer.
SEQUENCING : A act of recording digitally and manipulating the MIDI
information required to remotely play a synthesizer keyboard or similar
SERIES SPLITTER : An adaptor consisting of a plug and two sockets wired in
series. Enables two identical 110 Volt loads to be safely run from a 240 Volt
1) To prepare the stage for action. (verb)
2) The complete stage setting for a scene or act. (noun)
SET BACK : To reset technical systems to a particular point in the show in
order to repeat a sequence or scene during rehearsals.
SETTING LINE : Imaginary line running across the width of the stage, in
line with the proscenium arch, which is marked on the groundplan and is used
as a reference when planning furniture layouts etc. Usually the furthest
downstage anything can be set without fouling the house tabs. See also Centre
SFX : Abbreviation for Sound Effects.
SHACKLE : See Rigging.
SHEAVE : The wheel in a pulley which carries the wire or rope.
SHIN BUSTER : The lowest lantern on a lighting boom. Named because of the
proximity of sharp parts of the lantern to the flesh of the lower leg.
SHOW RELAY : A network of speakers carrying the sound of the show, and
sometimes stage managers calls, to the furthest reaches of the theatre.
SHOW REPORT : A written report by stage management giving problems, running
times, show staff and audience numbers for the previous days' performance(s).
Copies are circulated to the technical departments and management staff.
SHUTTER : Accessory for a profile lantern. Metal blade which can be used to
shape the edge of the beam. Shutters (normally four) are located in the gate
at the centre of the lantern. Similar in effect to barndoors.
SIGHTLINES : A series of lines drawn on plan and section to indicate the
limits of the audience vision from extreme seats, including side seats and
front and back rows. Often marked in the wings as a guide to the actors and
SILK : A special type of diffusion filter which stretches the light in one
direction. Especially useful for lighting large cycloramas with a limited
number of lanterns, or for lighting an elongated object (eg a staircase) with
SILL : See Flat.
SILL IRON : A piece of flat iron screwed to the bottom rail of a door flat
which holds it together, and ensures that the flat doesn't warp. Invisible to
SINGLE PURCHASE : Counterweight flying system where the cradle travels the
same vertical distance as the fly bar. The counterweight frame therefore
occupies the full height of the side wall of the stage. See also Double
SIX LAMP BAR : An internally-wired lighting bar, designed for touring, with
six socket outlets terminated in a multi-way connector. Often pre-rigged with
lanterns (eg Parcans). Stored in Meatracks.
SIZE : See Scenic Paint.
SLIDE : See Projection.
SKIN MONEY : Extra payment made to actors/actresses when nudity is required
SKIP (Costume/Props): A large wicker basket or box, often wheeled, which
stores costumes and/or props for touring.
SMOKE MACHINE : Electrically powered unit which produces clouds of white
non-toxic fog (available in different flavours/smells) by the vaporisation of
mineral oil. Specially designed for theatre & film use. Vital for
revealing airborne light beams. See Cracked Oil, Dry Ice.
SMPTE (pronounced "Simptee"): Society of Motion Picture and
Television Engineers. A timecode for synchronising a piece of music etc on a
tape to almost anything else.
SNAP : A lighting or sound cue with no fade time - the cue happens
SNAP HOOK : A plastic or metal "S" hook used to hang tabs etc. A
sprung catch prevents the hook becoming detached.
SNAP LINE : Chalked piece of string which, when stretched tight and
"snapped" is used for marking straight lines on stage or on scenery
as a painting aid.
SNAPPER : See Grelco.
SOCAPEX : A multipin connector which can carry a series of lighting or
sound circuits. Very robust and designed for touring. Available in 19 and 37
SOFT LIGHT : Asymmetric flood light used as a fill light in TV studios to
eliminate shadows and balance the key light.
SOUND CHECK : A thorough test of the sound system before a performance.
This will include checking each speaker cabinet individually, and each
playback device. In the case of a live concert, this is the session when each
instrument is played in turn for the sound engineer to check and fine-tune the
SOUND EFFECT : See Effect, Sound.
SOUND REINFORCEMENT : Amplifying a voice just enough so that it can be
heard, without the audience being aware that it is being amplified (ideally
SOUND TO LIGHT : A facility which can link the effects panel on a lighting
board to an audio input which detects treble, mid and bass beats, and can
flash lights or trigger effects in time to those beats.
SPANSET : See Rigging.
SPEAKER : See Loudspeaker.
SPEAKON CONNECTOR : A type of shielded, locking multipin speaker connector
which can safely carry the high currents from an amplifier needed to drive
large speaker systems. Available in 4- or 8-way types, and ideal for
bi-amplified systems. The cable version of the connector is male, and the
panel mount connector is female.
SPECIAL : A lantern within the lighting rig which is required for a
specific moment or effect within the performance, and is not part of the
general cover lighting.
SPIGOT : An adaptor screwed onto the hanging bolt of an instrument to
enable it to be used on an upright stand.
SPILL : Unwanted light onstage.
SPILL RINGS : Concentric rings attached to the front of a beamlight (eg
Strand Pageant) to contain spill.
SPL (Sound Pressure Level) : A measurement of the loudness of a sound.
SPLICE : A join or edit in a sound tape. A splice may be between leader
tape and audio tape or between two pieces of audio tape. Splicing tape is the
adhesive tape used, a splicing block is used to hold the tape and guide the
single-sided razor blade when making the cut.
SPLITTER : See Adaptor.
SPOTLIGHT : General term for any lantern with a lens system. See Fresnel,
SPOT LINE : A temporary line dropped from the grid to suspend something in
an exact special position.
SQUELCH : Control on a radio microphone receiver for fine-tuning the
reception according to the surroundings.
STAGE ELECTRICIAN : Member of the electrics staff whose responsibility it
is to set or clear electrics equipment during scene changes. May also carry
out colour changes on booms etc.
STAGE LEFT / RIGHT : Left/ Right as seen from the Actor's point of view on
stage. (ie Stage Left is the right side of the stage when looking from the
STAGE MANAGER :
1) The Head of the Stage Management team comprising the deputy stage
manager (DSM) and assistant stage manager (ASM). The DSM is normally "on
the book" calling the cues from the prompt corner. The ASM supervises
props. Depending on the needs of the production, there may be a team of
stagehands, usually casual employees.
2) A software program by Richmond Sound Design which, via MIDI Show
Control, can be set up to "run the show".
STAGE SCREW : A large screw which is screwed through the "foot"
of a stage brace to secure it to a strong wooden floor. Only suitable for use
in theatres with non-precious wooden floors !
STAGE WEIGHT : See Brace Weight.
STAGGER-THROUGH : The first tentative attempt to run through the whole
show. Very rarely runs smoothly, hence the name.
STALLS : The lowest audience seating area, usually just below the level of
the stage, in a proscenium theatre.
STAND-BY : A warning given to technical staff by stage management that a
cue is imminent. Technicians acknowledge by saying "Standing By".
STARCLOTH : See Cloth.
STATE : In lighting terms, a lighting "picture" ; each lighting
cue results in a different state (or a modified state).
STEP : A control on some lighting effects boards which enables the operator
to "step" through a chase effect in time to music etc.
STILE : See Flat.
STRIKE : To take down a setting; to take down properties or lanterns.
STRIPLIGHT : A thin linear filament lamp similar to an Architectural, but
having contacts at the ends of the lamp. Available clear or opaque.
STROBE : Device giving a fast series of very short intense light flashes
which can have the effect of making action appear intermittent. Because strobe
lighting can trigger an epileptic attack in sufferers, the use of a strobe
must be communicated to the audience before the performance begins.
Regulations exist governing the maximum length of time for which a strobe can
SWAG : A particularly artistic way of drawing a set of tabs diagonally up
at the same time as flying them out. Looks much better than it sounds.
S.W.L. : Safe Working Load. The maximum weight that should be put onto a
lifting device or suspension point.
SUB-BASS : That part of a speaker system designed to extend the low
frequency range of the system.
When written as a single word -- spotlight -- it refers to lighting
instruments that produce a tightly focused spot light. Also used to refer to a
TABS: Reffering to a yearly publication booklet by Strand Electric.
TABS : Originally "tableaux curtains" which drew outwards and
upwards, but now generally applied to any stage curtains including a
vertically flying front curtain (house tabs) and especially a pair of
horizontally moving curtains which overlap at the centre and move outwards
from that centre.
TAB DRESSING : Lighting focused onto the house tabs.
TAB-TRACK : Track for suspending and operating horizontally moving
curtains. May be hand or winch operated.
TAKE-UP SPOOL : The empty reel on the right hand side of a reel to reel
tape deck onto which is wound the tape as it plays through the machine.
TALLESCOPE : A retractable alloy vertical ladder on an adjustable wheeled
base. The platform at the top is just large enough to hold one person. Used
for rigging lanterns, focusing etc. Collapsible enough to fit through a
standard doorway. Outriggers are used to stabilise the tower from falling
sideways. Two people are used to move and steady the tallescope.
TAPE LOOP : A continuous loop of tape which produces an
"everlasting" sound effect when played. Used for any long sound
needed (eg rain, wind) without having to continuously repeat a short effect.
TAT : (slang) Small (but still useful) offcuts of cloth or wood.
TEASER : Border, usually black, set behind the proscenium and linked with
tormentors to form an inner frame to the stage, and to mask the upper parts of
the fly tower.
TECHNICAL REHEARSAL : Usually the first time the show is rehearsed in the
venue, with lighting, scenery and sound. Costumes are sometimes used where
they may cause technical problems (eg Quick changes). Often a very lengthy
process. Often abbreviated to the Tech.
TECHNICAL RIDER : See Rider.
THROW : Distance between a light source (e.g. lantern or projector) and the
actor or object being lit.
THROW LINE : A rope used to hold adjacent flats together as one via cleats.
THRUST : Form of stage which projects into the auditorium so that the
audience are seated on at least two sides of the extended piece.
THUNDER RUN : Long channel down which a cannonball is rolled to give a
realistic thunder rumble effect. Built into the roof of some older theatres,
but mostly now unused (for safety reasons).
THUNDER SHEET : Large suspended steel sheet with handles which produces a
thunder-like rumble when shaken or beaten.
TIME : The facility on memory lighting boards for playing back timed fades
at the touch of a button.
TOPPING AND TAILING : See Cue to Cue.
TORMENTORS : Narrow masking flats adjacent and sometimes at right angles to
the proscenium arch.
TRANSDUCER : A device that converts energy from one form to another. A
microphone is a transducer that converts sound wave energy into electrical
TRANSFORMATION : An instant scene change, often effected by exploiting the
varying transparency of gauze under different lighting conditions.
TRAP : An opening through the stage floor. A grave trap is a lowered
rectangular section used in Hamlet etc. A cauldron trap is a simple opening
through which items can be passed into a cauldron on stage. A star trap is a
set of triangular sprung flaps in the stage floor through which an actor can
be propelled from a lift below stage.
TRAP ROOM : The area directly below the trapped part of the stage. Used for
accessing the traps.
TRANSVERSE : Form of staging where the audience is on either side of the
TRAVELLERS : Curtains or scenic pieces moving on horizontal tracks.
TREADS : General name for any stage staircase or set of steps. The step of
the staircase is called the tread, and the height of the staircase depends on
the number of risers. The length of the staircase is called the going. Treads
can be either open or closed string - meaning whether the riser is solid or
TRIPE (bundle) : Bunch of cables tied or taped together into a single unit.
1) Tough Rubber Sheath. Applied to any rubber-sheathed mains cable.
2) Tip Ring Sleeve. The three contacts on a stereo jack audio connector.
TRUCK : Wheeled platform on which a scene or part of a scene is built to
facilitate scene changing.
TRUNNION ARM : U-shaped bracket between the hook clamp and the main body of
a lighting instrument, enabling it to be tilted to any angle.
TRUSS : A framework of alloy bars and triangular cross-bracing (usually of
scaffolding diameter) providing a rigid structure, particularly useful for
hanging lights where no permanent facility is available.
TUBULAR WAVE RIPPLE : See Effects.
TUMBLING : Flying a cloth from the bottom as well as the top when there is
insufficient height to fly it in the normal way.
TUNGSTEN HALOGEN : A standard tungsten filament lamp loses its brightness
in its' lifetime. Tungsten Halogen lamps use a Quartz envelope
("bulb") filled with halogen gas to give an almost constant colour
temperature. See Halogen Cycle.
TWEETER :Part of a speaker system designed to handle the high frequency
part of the signal.
TWIRLIES : Derogatory (or not ?) term for performing members of a ballet
ULTRA VIOLET (UV) : Short wavelength source of light at the end of the
visible light electromagnetic spectrum which causes specially treated
materials to fluoresce on an otherwise blackened stage. Used for special
effect and for lighting onstage technical areas (eg Fly Floors). Ultraviolet
sources designed for stage use are known as Black Light sources and have all
harmful radiations filtered out.
1) The part of the stage furthest from the audience.
2) When an actor moves upstage of another and causes the victim to turn
away from the audience he is "upstaging". Also, an actor drawing
attention to himself away from the main action is upstaging.
USITT :United States Institute of Theatre Technology.
VAC FORMING : Vacuum forming is a process of reproducing architectural and
textural relief detail on sets by forming a thin plastic sheet into the
required shape by a suction process.
VARI*LITE : Trade name for a range of "intelligent" moving
VIDEO : See CCTV.
VISUAL CUE : A cue taken by a technician from the action on stage rather
than being cued by the stage manager. Often abbreviated to "Vis".
VOLTAGE : The pressure at which electric current is available. The UK
standard voltage is 240 Volts. The American standard is 110 Volts.
VOMITORY : An entrance or exit through banked seating. Often abbreviated to
VPLT :German Professional Lighting and Sound Association.
VU METER : (VU - Volume Unit). Pointer and scale meter which indicates the
average level of a signal. Misses any transients and spikes that lead to a
clipped signal. See PPM.
WAGON STAGE : Mechanised stage where the scenery is moved into position on
large sliding trucks (wagons) as wide as the proscenium opening, from storage
in large areas to the side and rear of the main stage. This system enables
incredibly complex and otherwise time-consuming scene changes to occur almost
WARDROBE : The general name for the costume department, its staff and the
accommodation they occupy.
WARDROBE PLOT : Actor-by-actor, scene-by-scene inventory of all the
costumes in a production, with a detailed breakdown into every separate item
in each costume.
WATER CRACKER : Device which produces a thin haze in the air by
"cracking" water droplets.
WATTS : Unit of electrical power derived from the current (or
"quantity" of electricity) multipled by the voltage (or
"pressure" at which the current is delivered). Stage lighting
equipment is rated in Watts (or Kilowatts - 1kW being equal to 1000W). This
refers to the amount of power required to light the lamp. A higher wattage
lamp requires more power and gives a brighter light output.
WAVELENGTH : The distance from one point on a vibrating wave to the same
point on the next wave. The lengths of the sound waves (wavelengths) we can
hear range from one inch to 40 feet. High frequency sounds have short
wavelengths (and are more directional), low frequency sounds have long
wavelengths (and are less directional). In lighting terms, blue light is short
wavelength, green is medium and red is long wavelength. Beyond visible light
are the short wavelength Ultra Violet light and the long wavelength Infra Red
light. See also Frequency.
WEDGE : A wedge-shaped foldback speaker. Angled so that it can sit on the
stage floor and point up at musicians/cast.
WEIGHT : See Counterweight and Brace Weight. Also, instruction given to
rookie stage crew on errand to hardware supplier ; "Go and get me a long
WHISTLE : Backstage whistles were originally used to give instructions to
the sailors who (because they knew the best knots) had the job of operating
the theatre's flying system. Nowadays, whistling is forbidden backstage
because it might result in a lost sailor cutting a rope and dropping something
WHITE NOISE :
1) The out of view areas to the sides of the acting area.
2) Scenery standing where the acting area joins these technical areas.
WIPE : Single curtain moving across the stage on a single track (wipe
track) rather than paired curtains on a tab track.
WIRE ROPE : Fine steel wires woven into a rope to give great strength. A
kink or a knot in wire rope greatly reduces the strength.
WOOFER : Part of a speaker system designed to handle the low frequency
parts of the signal.
WORKING LIGHTS :
1) High wattage lights used in a venue when the stage / auditorium lighting
is not on. Used for rehearsals, fit-up, strike and resetting.
2) Low wattage blue lights used to illuminate offstage obstacles and props
tables etc. Known as Wing Workers.
WORKSTATION : A synthesiser keyboard which also contains a sequencer and
other MIDI software.
X : Stage management abbreviation for "crosses to".
XFADE : See Cross Fade.
XLR : Multipin metallic audio connector. (3 pin for normal sound use, 5 pin
for DMX, Colour Scrollers etc). Sometimes called Cannons after the original
manufacturer. See balanced line. The UK standard for wiring the 3 pin
connector is as follows : Pin 1 (Screen), Pin 2 (+ve / "hot"), Pin 3
(-ve, "cold"). (Xternal, Live, Return).
YO-YO : A device used for remotely moving a gobo in one plane whilst it is
in the lantern. Gives the effect of a lateral movement (door opens, train
ZERO DB : The common reference point when discussing sound levels. Levels
above 0dB are expressed as positive (+5dB) and those below as negative
ZOOM PROFILE : A type of profile lantern with two lenses enabling the
adjustment of both size of the beam and whether it's hard or soft focus.
Essential when working with gobos.
Parts of this listing compiled by email@example.com. and aknowledgement
is herby given.
Parts of this listing is copyright (c) 1996/97 Jon Primrose / Exeter
University Drama Department. The most up to date version can be downloaded from
Exeter University Drama Department information : http://www.ex.ac.uk/drama/
Compilation and additions in part by H.A. Lautenbach I.E.S.-S.W.A.C. Strand
Century Lighting, Strand Electric, The Rank Group, Ash-Stevenson Inc.
Aknowledgement also goes out to:
All reproduction must include this statements.