This is a cute late 1970s disco-era skit. Several muppet monsters are dancing to the music in a disco. Another green monster enters the room and asks, "Is this the home of Sesame Street fever?" Ignored by the dancing crowd, he tries to join in with them. When the lyrics of the song begin to say "out, out, out the door," the entire crowd begins to dance out the "out" door. When the lyrics say "in for more," the crowd dances back inside through the "in" door. Unfortunately, our green monster friend has trouble figuring out what's going on, and gets hit by the "in" door as it opens.
The song is OK, especially if you like disco. Below are the main lyrics:
In, out, that's what the song is all about (2x)
Out, out, out the door. Out, out, out out the door (2x)
In for more, in, in, in, in for more (2x)