Proscenium

A proscenium (Ancient Greek: προσκήνιον, proskḗnion) is the virtual vertical plane of space in a theatre, usually surrounded on the top and sides by a physical proscenium arch (whether or not truly "arched") 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.

In the Greek and Roman theatre, no proscenium arch existed, in the modern sense, and the acting space was always fully in the view of the audience.

It has a plain proscaenium at the front of the stage, dropping to the orchestra level, now usually containing "stalls" seating, but no proscenium arch.

However, the Teatro Olimpico's exact replication of the open and accessible Roman stage was the exception rather than the rule in sixteenth-century theatre design.

Parma has a clearly defined "boccascena", or scene mouth, as Italians call it, more like a picture frame than an arch but serving the same purpose: to deineate the stage and separate the audience from its action.

[citation needed] While the proscenium arch became an important feature of the traditional European theatre, often becoming very large and elaborate, the original proscaenium front below the stage became plainer.

What the Romans would have called the proscaenium is, in modern theatres with orchestra pits, normally painted black in order that it does not draw attention.

[3] There is no evidence at all for this assumption (indeed, contemporary illustrations of performances at the Teatro Olimpico clearly show that the action took place in front of the scaenae frons and that the actors were rarely framed by the central archway).

The result is that in this theatre "the architectural spaces for the audience and the action ... are distinct in treatment yet united by their juxtaposition; no proscenium arch separates them.

Prior to the use of proscenium stages, early court ballets took place in large chambers where the audience members sat around and above the dance space.

Interior view of a theater.
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 proscenium ) 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.
War Memorial Opera House in San Francisco , with a large golden proscenium arch, from which the stage curtains hang. The drop from the stage to the orchestra pit, the proscaenium to the Romans, is in contrast painted black and given no emphasis at all.