Alex Harvey (February 5, 1935 - February 4, 1982) was a Scottish rock artist, best known as the lead singer of The Sensational Alex Harvey Band.
Harvey was a huge Zappa fan. He even performed and recorded a cover of Willie The Pimp on his album "The Joker Is Wild" (1972). In 1975 Harvey was opening act for Zappa during the 75/11/03 Philadelphia PA US Spectrum Theater show, but was promptly booed off stage.
According to this source Zappa once told a Scandinavian journalist that: "I just want to say there are only two bands in the world worth buying a ticket to: Frank Zappa and the Mothers of Invention and an English group called the Alex Harvey Band." .