For a guy who started out as an unreconstructed folkophile in a band called the Au Go-Go Singers, Stephen Stills has made a considerable impact on popular music. With Buffalo Springfield, he helped invent folk rock, and with CSNY he helped polish and further politicize it. As a solo artist, he has drawn on his Texas roots, defining a country-rock sound that's wilder and deeper than the Eagles at their very best. Thirty-five years on, his epic album Manassas, a stoned-but-smart rock and roots free-for-all, remains an overlooked classic and a definitive riposte to naysayers of '70s utopianism. Stills' best work is surely behind him, but his softly rasped, high tenor remains instantly recognizable.