Fosse lifted alot from this film-
When you look at the timeline, this came out before Sweer Charity and Cabaret. The shots from the stage wings, audience reactions, Fosse implemented in the above movies.
The cast in this is impressive. Robards is terrific, as usual. Too bad more people don't know about this movie, they might think it's cheesey and the style dated but it shows a part of entertainment history accurately-