The original prog rock band, King Crimson formed all the way back in 1968, with guitarist Robert Fripp the only member to stay the course since day one. Currently on their eighth lineup, the band has had no fewer than twenty-one members over the years, however that's not counting session and temporary players, which would take the band's count all the way up to thirty-five! That's a lot of changes for a band that, while not the most famous on this list, was extremely influential to the progressive rock and metal acts that followed it.