Give Out, Sisters (movie, 1942)

The Andrews Sisters headline this musical. They play the lead act at a popular nightclub. The trouble begins when they hire a few students from a financially foundering dance school for their newest production. One of the dancers, a rich young socialite, desperately wants to be in it too, but her prurient maiden aunts refuse to allow her to disgrace their family by becoming a common chorine. She and the club owner (who must have the aunt's permission because the girl is underage) try to convince them, but it's not easy.