Scrubs Easter Egg - Scrubs Theme Tune

In Season 8, episode 6 (My Cookie Pants), near the beginning when J.D comes back to the apartment and stands on the Piano Mat (which Elliot put out as a Burglar Alarm) and then went back to it and plays a tune, which in fact is the "I'm no Superman" part of the opening song, which is followed by him saying "That's Catchy."