Coming home from his show, Jack receives a message to call a Dr. Johnson. The doctor asks him to come right over. Dr. Johnson is a psychiatrist who has found a man with amnesia who keeps repeating Jack's name. Jack identifies the amnesia victim as Professor Le Blanc, his old violin teacher; in flashback, we see he has gone crazy because Jack plays so badly. To cure Le Blanc, Jack plays his violin beautifully, and Le Blanc, realizing he is not a failure as a violin teacher, recovers. Jack asks the doctor not to reveal that he is such a good violinist because he has made so much money as a bad one. (thetvdb.com)