David Crosby: 12 essential songs

David Crosby was a crucial voice of both the hippie idealism and the world-weary realism of the classic rock era. As a founding member of the Byrds and later Crosby, Stills, Nash & Young, he helped invent folk rock and country rock in the 1960s and was instrumental to the sensitive singer-songwriter scene of the 1970s; his singing and guitar playing broadened the way people thought about pop music's meaning even as it helped create a culture in which rock stars were encouraged to enjoy every earthly excess available.