A mousy, poor manicurist seeks to switch places with her more glamorous, wealthy twin sister.
Gangster Johnny Carmenta must confront the "Charro of the Slums" Pancho Domínguez, who has control over the city, but their rivalry gets worse when rumba dancer Rosa befriends both men.
After listening to the waltz "Carmelita", dedicated to his wife, President Diaz instructs Don Susanito seeking the composer Chucho Flores to give her a piano. Don Susanito located Chucho, a bohemian who lives drunk and surrounded by poets and artists. Don Susanito was named patron protector of artists and aspiring young stars of the stage, which leads to a series of adventures in the middle of songs, dances and loves.
