Jack has pre-concert jitters because he is to play Carnegie Hall in an hour. He gets a visit from old friend Spike Jones. Afterwards, Jack falls asleep and dreams that Mendelssohn tells him that he plays the violin beautifully. Jack wakes, then sleeps again; this time, he dreams the Devil (George Burns) tells him he can make Jack the greatest violinist of all time. Jack begins to play with the orchestra, but after a few members leave, Jones takes over the conductor's podium, and crazy music and comedy ensue. In the end, Jones shoots Benny and he is carried away on a stretcher, still playing.