On Moguls and Movie Stars (sorry I don't remember which timeframe, guessing 20-mid 30s) they showed a few parts of a black and white movie. All I can remember about it was that there were lots of what I think were ballerinas all performing choreographed movements. They were all wearing white and I always thought it was "Swan Lake" but after some recent searching I found that it wasn't. I know it's vague, but can anyone think of what this movie is?