The "Mah Nà Mah Nà" song, made famous by the Muppets, actually originated in a racy Italian film from 1968 called Sweden: Heaven and Hell. This softcore "mondo" documentary, narrated by Edmund Purdom, delves into some steamy themes and tackles controversial topics like teenage contraception, lesbian nightclubs, and wife-swapping in Sweden. It also examines issues like drug use, alcoholism, and suicide in the country. The song was later adopted by Jim Henson who debuted the beatnik Muppet character known as "Mahna Mahna" on The Ed Sullivan Show on November 30, 1969.
Jones says by August 1969, it had made its way to a run at the Avco Embassy East theater on East 58th Street. By early October, Henson and Frank Oz — the legendary puppeteer who gave voice to Cookie Monster, Fozzie Bear and Yoda — had popped in to watch it.
Just a few months later in November, the song made its debut on "Sesame Street," crooned by a bedraggled, hairy little Muppet and two other Muppets with little girl dresses, high voices and long hair.
That was followed that same month by the version we all now know, which debuted on "The Ed Sullivan Show."