Even more obscure? How about a band that never made it past the Demo Tape phase, rejected by record companies. A few years back I stumbled across this one, and later tracked down one of the original Demo Tapes online and added it to my collection of music.
Almost as obscure, a song by Tattoo Rodeo that only ever played in a movie, wasn't on the Soundtrack and wasn't on any albums. The movie itself was a pretty crappy B rated cheesy action movie that had an all-over-the-place plot, but I managed to track down an original copy for a friend who collects music like I do.