I finally saw it last night and there was a bit of his singing and dancing but I think that was important to the plot rather than it being written into everyone of his contracts!
You know it's a good film when you assume it's American but are wonderfully surprised to see that absolutely EVERYONE (except Zefron and Claire Danes) in it is British. That guy who makes a living playing Orson Welles on stage must be well chuffed that he has played him on screen, it was an amazing performance, the main reason to see the film definitely! And like I say the ensemble were excellent, Eddie Marsan, Ben Chaplin and Kelly Reilly all fabulous support. It's a film about the theatre and it was well done, I loved it.