[youtube]https://www.youtube.com/watch?v=57hbgQJcdac[/youtube]

Strange little band from 1970's Germany.  They didn't keep a consistent sound between albums which probably contributed immensely to their obscurity, but damn they were good.  
Their first album (self-titled) is a must listen for anybody who has even a passing interest in Proto-Metal.  It was like Deep Purple and Sabbath had a loud, heavy, wailing baby.