I can't remember who first told me that not only was this song sung and played at the witches' sabbat Back When, but that, in fact, it actually describes the uncanny goings-on there.
The reason for the song's witchy reputation is unclear. The sheer unreality of the scenario? The implied masquerade? The tune's leering allusion to the plainchant Dies Irae?
Well, whether witches capered to this tune in the old days or not, we certainly do now. In fact, we'll be singing and dancing it at the upcoming Midwest Grand Sabbat this year. With luck, the Devil's Piper himself will be there to play.
Of the many different versions of this song that exist, what follows is the oldest known to me, given in Medieval French, English translation, and singable English lyrics.
Grab your bagpipe and play along.