S1·E6 A Legacy of Amadeus

After waking Roger up with her piano playing, Roger decides to take Dorothy to see a friend who can help her learn to add feeling to her playing. His friend is a robot named Instro, who was built by a scientist named Amadeus and thought of Instro as a son. Instro remembers how happy Amadeus was when Instro would play the piano for him. While Instro is giving Dorothy a lesson, a mysterious stranger arrives and reminds Instro that he needs to fulfill his creator's legacy.