

Shell: A hard, often removable surface, designed to reflect sound out into the audience for musical performances.Safety curtain: A heavy fireproof curtain, in fiberglass, iron or similar material placed immediately behind the proscenium.Rake: A slope in the performance space (stage), rising away from the audience.Prompt corner: Area just to one side of the proscenium where the stage manager stands to cue the show and prompt performers.Portal or Proscenium Arch: An open frame on a proscenium stage that divides the audience from the stage in traditional Western theatres.

Typically, the plaster line runs across the stage at the back face (upstage face) of the proscenium wall. Plaster Line: An imaginary reference line on the playing area that indicates where the proscenium arch is.Crossover: The area used by performers and technicians to travel between sides of the stage out of sight of the audience sometimes created onstage with flats, or masking and drapery.Typically this refers to areas directly accessible from the stage and does not include spaces such as the control booth or Orchestra pit Backstage: Areas of the theatre adjacent to the stage accessible only to performers and technicians, including the wings, crossover, and dressing rooms.Apron: The area of the stage in front of the proscenium arch, which may be small or, in a thrust stage, large.

Note that for performance spaces with audiences in more than one orientation, typically one direction is arbitrarily denoted as "downstage" and all other directions reference that point. Typically this refers to spaces accessible to the performers but not the audience, such as the wings, crossovers, and voms. Offstage: The area surrounding the playing space not visible to the audience.Onstage: The portion of the playing area visible to the audience.Center Line: An imaginary reference line on the playing area that indicates the exact center of the stage, travelling from up to downstage.

