Hi. To the best of my knowledge, that song was never officially published anywhere; and so far I've never heard of it being used outside of the Muppet show. According to the script for the show it was written by Doug Hennings' wife (at that time). So I would guess your best bet might be to find somebody with a good ear to pick out the chords/melody for you -- the number is readily available on youtube I think. I'm sorry I can't help more with it!