Editing Proscenium (section)

{{Short description|Theatre feature}}
{{for|the Atlanta office tower|The Proscenium}}
{{more citations needed|date=October 2015}}
[[File:Chicago Auditorium Building, interior from balcony.jpg|thumb|The proscenium arch of the theatre in the [[Auditorium Building (Chicago)|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'').|alt=Interior view of a theater.]]

A '''proscenium''' ({{langx|grc|προσκήνιον}}, {{Transliteration|grc|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 (theatre)|stage]] during a theatrical performance.  The concept of the [[fourth wall]] of the theatre stage space that faces the audience is essentially the same.

It can be considered as a [[Social constructionism|social construct]] which divides the actors and their stage-world from the audience which has come to witness it.  But since the curtain usually comes down just behind the proscenium arch, it has a physical reality when the curtain is down, hiding the stage from view. The same plane also includes the drop, in traditional theatres of modern times, from the stage level to the "stalls" level of the audience, which was the original meaning of the ''proscaenium'' in [[Roman theatre (structure)|Roman theatre]]s, where this mini-facade was given more architectural emphasis than is the case in modern theatres.  A proscenium stage is structurally different from a [[thrust stage]] or an [[Theatre in the round|arena stage]], as explained below.