And here is a bit of history behind the song, for some of you who may remember it from other venues. From Wikipedia:
"Mah Nà Mah Nà" is a popular song written by Piero Umiliani. It originally appeared in the Italian film Sweden: Heaven and Hell (Svezia, inferno e paradiso). It was a minor radio hit in the U.S. and in Britain, but became better known in English-speaking countries from its use in a recurring blackout sketch for the 1969-70 season of The Red Skelton Show, the fourteenth episode of Sesame Street, and the first episode of The Muppet Show.