Borrah Minevitch and His Harmonica Rascals(1935)

A Warner Bros.-Vitaphone Melody Master: The harmonica band is offered a radio gig... by their landlord! Their imaginations take them to various settings: aboard a train with a porter who can "gibber" a melody with the best of them, on the air with the leader making good use of the microphone and a hilarious slapstick battle resulting and, finally, in a Spanish setting with the shortest player (the comedy star) encouraging the dancer to show more "leg" than his boss allows.