When boisterous Judy Bellaire (Judy Garland) encourages her fellow school chorus members to sing a classical piece with a modern swing beat, her scandalized teacher uses the musical mutiny as an excuse to expel her from the Colvin School for Girls. With the encouragement of Ricky Saboni (Allan Jones), her family's cook, Judy decides to follow her dream and audition for a stage musical. Meanwhile, Ricky struggles to gain the affections of Judy's sister, the lovely Sylvia (Lynne Carver).