This movie is about when sound pictures were starting to take over and people weren't going to live theater anymore. They used to put on "prologues" before movies - short musicals that were connected to the story of the movie in some way. James Cagney (*LOVES*) plays the guy who has to come up with all of the ideas for musicals. The "cat" number is hilarious.
This is a great, great musical, and one of those typical 1930s musicals where the characters have to put on a show and manage to put together an incredibly complex number or set of numbers in a ridiculously short amount of time. There are a couple of cute romances in it, especially the love triangle with Cagney's character. Joan Blondell is gold, and has some of the best lines ("I know Miss Bi-- I mean, Rich" - PWND!).
Oh, and speaking of impossibly complex musical numbers, I have two words for you - Busby Berkley. He designed all of the numbers, and if that name means anything to you, you know what I'm talking about. The whole idea is that these are "prologues" that happen before the movie, right? So this is all taking place on the little stage in front of the screen, right? There's no frickin' way that some of those sets would be happening on a stage. Especially the extensive waterfalls and built-in swimming pools. A very fun movie, though. This is going on my to-buy list.