Broadway Melody of 1940

In New York City, the dance team of Johnny Brett and King Shaw are at the bottom of the heap, and barely scraping by in dance halls. When a producer, Bob Casey, catches sight of Brett's moves, he wants to cast him as the dance partner of the Broadway star Clare Bennett . However, after some misdirection and confusion, Shaw becomes Bennett's partner instead, but Brett still has some dancing to do when Shaw fails to perform.