L. Ron Hubbard
L. Ron Hubbard himself. Yeah, seriously. It's weird enough that Charles Manson had a brief stint as a musician, but L. Ron fronted The Apollo Stars and put out a solo album (and soundtrack to his book Battlefield Earth) called Space Jazz, and it's pretty freakin' weird.
Stanley Clarke and Chick Corea teamed up as Return to Forever, composing a jazz fusion album dedicated to L. Ron, which is actually pretty interesting. Some YouTube commenters call Return to Forever "the fucking Dream Theater of jazz," which we're pretty sure is supposed to be a compliment (if a chronologically challenged one).