Whats that judy garland movie from the 40's?

im pretty sure it was her, it was definately after the wizard of oz, she was older, there was a man tryna teach her to dance but she didnt know her lefts and rights so he put a rubber band around one of her ankles, and she said it was too tight he was like "you look like your in pain" and she said "i am the rubber bands too tight" what movie was that