"I could drop dead in the middle of this conversation," says Graham Nash. "But on the other hand so could you, no matter how old you are," he adds with mordant evenhandedness. Don't worry, the folk-rock elder statesman who's been one-third of Crosby, Stills & Nash since 1968 is just fine. "I have no intentions of leaving," he assures, "my health is pretty damn good. But you know what I mean."