They Shall Have Music (1939)

Young Frankie (Gene Reynolds), a victim of a squalid life in the slums, fancies himself a tough guy until hearing a performance by violinist Jascha Heifetz (as himself). Inspired by the maestro, Frankie returns to his violin, an instrument his late father had taught him to play as a baby. After his cruel stepfather smashes the instrument and threatens to send the boy to reform school, Frankie runs away from home and stumbles upon a music school for underprivileged children run by kindly Professor Lawson (Walter Brennan) and his daughter Ann (Andrea Leeds). Impressed by Frankie's natural ear, the professor enrolls the boy in school and offers him refuge from the streets. Unknown to the Professor, the school's existence is threatened by Flower, one of its creditors, who insists that the school charge tuition or he will shut it down. When Frankie overhears Ann and her boyfriend, Peter McCarthy (Joel McCrea), discussing the dismal financial situation, he organizes the pupils to perform on the street. After hearing one of their concerts, Heifetz shows an interest in the school, and Peter, to put off his creditors, tells them that Heifetz will perform at the children's concert.