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Theatre Glossary

Theatre Glossary

These pages provide explanations of terms used in this website, and attempt to link North American and European / British terms in something of a cross-reference. As Mike’s background stems from technical theatre, this glossary is biased towards technical theatre terms, and those used throughout the pages of this website.

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Act Curtain / Act Drop
A curtain behind the fireproof curtain, and behind the grand drape, if there is one, closing the proscenium opening, and raised (or drawn) to reveal the stage during an act or scene.
Primarily UK term; see Forestage.
Arbor / Cradle
An arbor is part of a counterweight scenery flying system and balances the weight of the batten/bar and attached loads/scenery to enable them to be flown in and out of view of the audience in a controlled manner. Called a cradle in the UK.
Atmospheric Theatre
Majestic Theatre, San Antonio, Texas
Majestic Theatre, San Antonio, Texas
Atmospheric theatres were an auditorium design style particularly popular in the US during the 1920s. They were designed and decorated to evoke the feeling of a particular time and place, often an exotic outdoor garden setting, with stars twinkling above and moving clouds slowly crossing the ceiling, Fore more details check out Mike’s Atmospheric Theatres page.
Asbestos (Fire Curtain)
See Fire / Safety Curtain.


Baby Spot
A small spotlight, generally 500W or equivalent and intended for short throws and small theatres and school auditoria.
Back of House (BOH)
The non-public areas of a theatre building. Depending on the theatre the term may not be limited to just backstage areas (e.g. stage, dressing rooms, band room, scenic workshop, flies, grid) and may also include non-theatrical non-public areas of the building such as heating/cooling plant rooms, ceiling void, offices, etc.
Backcloth / Backdrop
A large curtain, usually painted to represent the sky, a landscape, or some other background, dropped upstage of all the set pieces to form the rearmost part of the setting. A backdrop painted to look like the sky is called a Skycloth, also a Cyclorama – although strictly speaking a cyclorama is a wrap-around affair, not a straight backdrop parallel to the stage opening.
The collective parts of a theatre building behind the divide (typically a proscenium arch) with Front of House areas, but often not really referring to the stage itself. For instance dressing rooms, green room, band room, scenery storage, workshops, etc.
The auditorium seating section at a height above the main floor level. Theatre auditoria generally have one, two, or three balconies.
A stereopticon device manufactured by the US-based Brenkert Light Projection Company in the 1920s. Using the tagline “Projects Everything but the Picture”, Brenographs were sold to most major US movie theatres in the early 20th century. The Los Angeles Theatre has a working F7 Master Brenograph in situ, and the Fox Theater in Bakersfield has an F7 Master Brenograph stored in pristine condition.


Cradle / Arbor
A cradle is part of a counterweight scenery flying system and balances the weight of the batten/bar and attached loads/scenery to enable them to be flown in and out of view of the audience in a controlled manner. Called an arbor in the US.
The technique of smoothly fading the lighting on the stage from one “look” to another.
Cue Light
Stop/Go indicator light used generally backstage to communicate when a given action (a “cue”) is to be executed. All cue lights are normally under the control of the person following the book of, or calling, the show. Cue lights are common in the Flies and Orchestra Pit whose staff often find it challenging to be available on backstage audio communications systems. Centralized cue lights can also be used for coordinated moves by stage crew, not all of whom may be looped in to backstage audio communication systems. Cue Lights can also serve as a backup when primary audio backstage communication systems fail.
Curtain Line / Plaster Line
The line of the main drape or front curtain, and the point from which upstage/downstage measurements are traditionally taken from. The Plaster Line is used for the same purpose in the US.
A backdrop painted to look like the sky. Strictly speaking a cyclorama is a wrap-around affair, not a straight backdrop parallel to the stage opening which is more correctly called a Skycloth.


Dead Hung
A flown piece which is suspended without ability to adjust its height without changing the suspension itself.
Common name for the stage floor, or a temporary show floor laid on top of the permanent stage floor.
The area of the stage closest to the audience.


Effects Projector
A high power light fixture which accepts various mechanical effects units (examples being undulating sea waves, waving flags, and most commonly rotating glass discs such as clouds, rain, and fire), using an objective lens to project the effect.
An ellipsoidal reflector spotlight (ERS), chiefly North American term. Ellipsoidal light fixtures project a generally hard-edged circular beam of light, can accept patterns/gobos, and come in either fixed beam angles or zoom lens versions (the latter being more common in the UK). Common fixed beam angles are 5° / 10° / 19° / 26° / 36° / 50° / 90°.


Fanchon and Marco
Fanchon and Marco Idea
Fanchon and Marco Idea
A brother and sister Vaudeville act who played the Orpheum Circuit in the late 1910s. Fanchon and Marco started producing their own shows (called Revues) starting in 1919, before embarking on producing larger theatrical extravaganza productions called Prologues. These were full live stage shows made for the nation’s movie palaces to be performed before the feature film in the 1920’s and 1930’s. The Fanchon and Marco prologue productions were called Ideas. There were up to 52 Idea productions a year, which included elaborate staging, acrobatic teams, vaudeville acts, dancers, and singing performances all related to a single theme, concept, or idea of the feature film they were supporting. For lots more about Fanchon and Marco visit the Fanchon and Marco website Link opens in new window.
Fire Curtain
A Fire Curtain (called a Safety Curtain or Iron in the UK) is a fire resistant curtain placed between the auditorium and the stage area, designed to segregate each area from the other to prevent or delay a fire reaching from one area to another.
A flat (short for scenery flat) or coulisse is a flat piece of theatrical scenery which is painted and positioned on stage so as to give the appearance of a background. Flats can be soft covered (covered with cloth such as muslin) or hard covered (covered with decorative plywood such as luan). Hard-covered flats are commonly used for television and permanent or touring theatrical productions; soft-covered for short-lived stage productions.
Fly Floor
The Fly Floor is a raised area on one side of a stage from which the scenery flying system is operated, and/or rigging may be arranged on a temporary basis for a production. In a theatre which has a counterweight flying system, the system usually has an operating position from the Fly Floor. In North American it is common to have operating positions (a lockrail) for counterweight flying systems both on the Fly Floor and at stage level. Manual hemp flying systems are generally only operated from the Fly Floor due to the increased space required for operators and weights.
UK terminology for a spotlight with operator who is charged with using the spotlight to follow the talent on-stage. Commonly referred to as “Limes” in the UK, from the time when lime was super-heated to emit a brilliant white light which was captured inside a lantern and focused to follow the talent on-stage. Generally called a spot or spotlight in the US.
Forestage / Apron
The area of the stage in front of the curtain line. Also called an Apron (primarily UK).
Front of House (FOH)
The public areas of a theatre building, e.g. auditorium, bars, restrooms/toilets, cloakrooms, reception rooms, lobbies/foyers, and box office.


Commonly the rearmost section of the topmost balcony in an auditorium; the “Gods”, or “cheap seats”.
A loosely-weaved somewhat transparent backdrop which appears to the audience as being solid if lit only from the front (and best at a near-parallel angle to the backdrop) however appears almost transparent when there is no front lighting, and objects behind the gauze are lit. Very popular for transformation scenes in British Pantomime. Called a scrim in North America
Grand Drape
North American term for the main house curtain, called House Tabs in the UK. Also known as the proscenium curtain or main rag.
Grid or Gridiron
The Gird (or Gridiron, chiefly in North America) is a grate of girders in the upper ceiling of the stagehouse from which all suspended/flown pieces hang from. Spans are placed close enough together such that one may walk (carefully!) upon the grid while still allowing spaces for suspension cables to drop down to the stage.
Gobo (Pattern)
Glass Moon Gobo
Glass Moon Gobo
A gobo (normally accepted as being an abbreviation for Go-Between) is a piece of metal or glass with a pattern cut or etched into it, blocking out parts of the light and allowing other parts to pass. Glass gobos allow for the use of graduated patterns, such as a photo-realistic depiction of a Full Moon. Placed at the focal point of a light fixture, the pattern may be projected in hard focus onto a stage surface. Pattern is a chiefly North American term.


A type of rope used for flying, made from fibers found within the bark of the cannabis plant.
Hemp Set
The simplest type of scenery 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..
House Border
The masking border immediately upstage of the house header (chiefly UK term), known as the valance in North America.
House Header
UK term for a theatre’s [ornate] frontmost border, usually matching the house tabs in design. Called the lambrequin in North America.


UK term for a Safety or Fire Curtain.


A adapter to convert one form of connector to another, whether for electrical power (most common), audio, video, etc.


Klieg or Klieglight
Outdated but still used North American term for any powerful and bright spotlight. Originally, a carbon arc spotlight developed by John and Anton Klieg and used extensively in Hollywood.


Structural unit at the side of the stage, commonly flown, for hanging side-lighting light fixtures from. May be dead hung or flown on the scenic flying system.
North American term for a theatre’s [usually] ornate frontmost border, usually matching the Grand Drape in design. Called a house header in the UK.
The action of joining two flats together (side-by-side) by hooking a line attached to the top of one of the flats around cleats or nails on the rear of both flats.
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..
Legitimate Theatre
Professionally produced stage plays as distinguished from films, variety shows, music hall, and theme park performances.


Music Hall
A form of variety entertainment popular in Britain from around 1850, consisting of singing, dancing, comedy, acrobatics, and novelty acts. Its popularity declined after World War I with the rise of the movie industry. Generally known as Vaudeville in the US.
Main Rag
See Grand Drape.


A lighting circuit which is switched rather than dimmed. Used for on/off and/or non-resistive loads such as smoke machines, small practical lights, smoke/haze machines, etc.


Off Broadway
Said of professional theatres in New York City, not located in the traditional Broadway theatre area.
When referring to the stage, an area towards the nearest side of the stage from the center. When not referring to the stage, the area not visible from the audience.
The stage area visible from the audience.
Open White or O/W
A lighting fixture which has not color filter, diffuser, etc, in it is said to be open white.
Orchestra Pit / Pit
The area, traditionally directly in front of (and sometimes extending underneath) the stage, where the orchestra sits. Normally at a level lower than the stage, and commonly lower than the main floor audience seating level.


Pantomime is a type of musical comedy stage production designed for family entertainment. Pantomime’s history reaches back to Punch and Judy shows and Music Hall - the UK equivalent of Vaudeville. Pantomime is often the first exposure children growing up in the UK have to live theatre.
Common abbreviation for Orchestra Pit.
Plaster line
Rear side of the Proscenium, and the line from which upstage/downstage measurements are traditionally taken from in US theatres (see Curtain Line for an equivalent in UK theatres).
Proscenium / Proscenium Arch
The arch framing the opening of the stage in traditional theatres. Also known as a Proscenium Arch (primarily UK).
Proscenium Curtain
See Grand Drape.


See Cue Light.


The gradient of a non-level stage floor. A common stage rakes is 1:24, however steeper rakes such as 1:17.5 have been known (example: Citizens Theatre, Glasgow). The Richmond Theatre in London has a main stage raked at 1:24 with the apron being raked more steeply at 1:18.
Rear of House (ROH)
Same as Back of House.
Regional Theatre
Said of theatres of a particular region, or of theatres in general outside of major theatrical centers, individually or collectively.
A form of organization, 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.


Safety Curtain
Safety / Fire Curtain
Safety / Fire Curtain
UK term for a Fire Curtain or Iron.
Chiefly North American term. See gauze.
Incorrect literal interpretation of “Cyc”, the abbreviation for Cyclorama. Can be seen in some Scottish Rite theatres including the Pasadena Scottish Rite.
A backdrop painted to look like the sky. Commonly used interchangeably used with the term Cyclorama, however strictly speaking a Cyclorama is a wrap-around affair, not a straight backdrop parallel to the stage opening.


Tabs / House Tabs
Originally referring to a tableaux curtain but long-used chiefly in the UK to refer to the main house curtain (often called the grand drape in North America).
Tab Warmers
Lights specifically focused to highlight the house tabs.


The area of the stage furthest away from the audience; the rear of the visible stage area.


North American term for the first masking border immediately upstage of the lambrequin. Usually black, it squares-off the stage opening behind the ornate lambrequin. If there is any term in the UK for this it would be the house border (the house header being the UK equivalent of the lambrequin).
A type of entertainment popular chiefly in the US in the early 20th century, featuring a mixture of specialty acts such as burlesque comedy and song and dance. Generally known as Music Hall in the UK.


The backstage department responsible for dealing with costumes and shoes for the actors.
The area at either side of the stage, out of sight of the audience, generally inferred to be at stage level. Actors waiting to make their entrance are said to be “waiting in the wings”


See Cross-Fade.



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