From the Wikipedia article:
“Mah Nà Mah Nà” debuted as part of Umiliani’s soundtrack for the Italian mondo film Svezia, inferno e paradiso (Sweden: Heaven and Hell) (1968), a pseudo-documentary about wild sexual activity and other behaviour in Sweden.
And you always thought The Muppets Show was for kids…
Various YouTube clips here.
October 2, 2010. Kinetic Skulpture Race Parade, Pete Townsend, Washington.