Neil Young has paid tribute to David Crosby, his longtime frenemy and bandmate who died Thursday at 81. “David is gone, but his music lives on,” Young wrote. He went on to call Crosby the “soul of CSNY,” referencing their super group of Crosby, Stills, Nash, & Young who dominated rock music in the late ’60s and early ’70s, with Crosby featuring as a singer and guitarist. “His great songs stood for what we believed in and it was always fun and exciting when we got to play together,” Young wrote. “We had so many great times, especially in the early years. Crosby was a very supportive friend in my early life, as we bit off big pieces of our experience together. David was the catalyst of many things.” Young’s touching tribute came a day after Graham Nash, another member of CSNY, wrote on Facebook that he was feeling “a deep and profound sadness” over Crosby's death.