The black network (1936)

The owner of a shoe polish company sponsors a radio show that showcases black performers. Since his wife's father put up the money to be the sponsor, she insists on singing on the show. She goes on after the main star, singer Nina Mae McKinney. The wife sings so badly that the sponsor's customers abandon him. He is forced to shine shoes on street corners, while Nina Mae and her boyfriend win a bet on a daily number and end up on easy street.