There was a pretty modern play, 1960s or 70s I think, that I cannot find.
It features a play-within-a-play, where the actors play as actors, playing as soldiers. Some of them go off stage to war and do not return, some of them get worried that there's more going on, and the whole play starts to become eerily real to them while their sergeant gets progressively more real about his job too.
Does anyone know of what I'm talking about here?
In the first scene, the fourth wall is broken as the actors pretend that the curtain has gone up early, then rush to get ready for their scene as soldiers.