Once called the mightiest supergroup of all time, David Crosby (the Byrds), Stephen Stills (Buffalo Springfield), Graham Nash (the Hollies) and later Neil Young (also of Buffalo Springfield) came together in the late 1960s to rock harmoniously. The two albums they produced (a self-titled debut with the original three members and Déjà Vu with Young) during their initial 15 months together dominated the U.S. rock scene at the time and still rank high in rock history today. Though their tours have shrunk in size since they played one of their first gigs before 500,000 screaming fans at Woodstock, all four members toured together in 2006, and the original three have a tour scheduled for the summer of 2010.