The story follows saxophonist Joe and bassist Jerry, two struggling musicians who witness the St. Valentine's Day Massacre while fleeing a police raid on a speakeasy owned mob boss "Spats" Colombo. Broke and in danger, they disguise themselves as women and join an all-female band. On the trip, they meet singer and ukulele player Sugar Kane, while both men become romantically entangled with her. When Spats and his gang arrive for a convention, the men's disguises are tested, leading to a chaotic chase.