When Gene Kelly was first booked for the show he said to the writers that he didn't just want to do 'Singin' in the Rain'. The writers turned Gene's request into a running gag for the show, and much to Kermit's dismay, Gene Kelly insists on just passively watching the Muppets do their "thing" from the wings of the stage. But of course, the Muppets get their way in the end, and Gene performs a few numbers while backstage with Kermit and the gang, including the song 'Singin' in the Rain'.