OK, this isn't (necessarily) folk, but Peter T's "obscure thread" and a film clip featuring Thunderclap Newman classic caused me to wonder about other one hit marvels.

So there is (as mentioned) Thunderclap Newman (remember seeing them on the Beeb's TOTP (Top of the Pops). Also Mungo Jerry, and Norman Greenbaum. Greenbaum has a web page marketing Spirit in the Sky - a whole industry arising from one song.

So any other nominations out there?

Rana