The showboat comes to town, piloted by Captain Benny. The William Tell Overture plays; we see a big steamship with "Show Boat" written on the side of it. A blackface quartet sings the title song. They introduce the conductor, who is a pig caricature of orchestra leader Paul Whiteman. The audience pelts him with tomatoes. One of the musicians plugs the pig's tail into a light socket so he conducts at super speed. Then Captain Benny announces the start of the amateur hour, with an operatic cow and a tough guy reciting poetry with sound effects. Then comes a stuttering moron doing "g-g-g-go into your d-d-d-ance," who steals the gong and stuffs it down his pants so they can't get rid of him. The jerk is chased down the street by Captain Benny, who smacks him repeatedly on the gong in his pants.

A strong mouse says that he will become the heavyweight champion of the world. But his grandma (who is just as strong) doesn't want him to fight. So that night he sneaks off to the fight, which Granny hears on the radio. Granny is so concerned she goes to the arena to stop him from fighting...but fate plays a hand.