A proscenium is the metaphorical vertical plane of space in a theatre, usually surrounded on the top and sides by a physical proscenium arch and on the bottom by the stage floor itself, which serves as the frame into which the audience observes from a more or less unified angle the events taking place upon the stage during a theatrical performance. The concept of the fourth wall of the theatre stage space that faces the audience is essentially the same.
The proscenium arch of the theatre in the Auditorium Building in Chicago. The proscenium arch is the frame decorated with square tiles that forms the vertical rectangle separating the stage (mostly behind the lowered curtain) from the auditorium (the area with seats).
Roman theatre view: 1) Scaenae frons 2) Porticus post scaenam 3) Pulpitum 4) Proscaenium 5) Orchestra 6) Cavea 7) Aditus maximus 8) Vomitorium, Roman theatre of Bosra, Syria
View of the seating area and part of the stage at the Teatro Olimpico (1585) in Vicenza, Italy. No proscenium arch divides the seating area from the "proscenium" (stage), and the space between the two has been made as open as possible, without endangering the structural integrity of the building.
The "proscenium" (stage) at the Teatro Olimpico. The central archway in the scaenae frons (or proscenio) was too small to serve as a proscenium arch in the modern sense, and was in practice always part of the backdrop to the action on-stage.
In theatre and performing arts, the stage is a designated space for the performance of productions. The stage serves as a space for actors or performers and a focal point for the audience. As an architectural feature, the stage may consist of a platform or series of platforms. In some cases, these may be temporary or adjustable but in theaters and other buildings devoted to such productions, the stage is often a permanent feature.
Stage of the War Memorial Opera House in San Francisco
Stage of the Polish Theatre in Bielsko-Biała
Stage of the Polish Theatre, Warsaw
A mentalist on a stage apron in a mind-reading performance, 1900
