David Crosby

David Crosby is a singer-songwriter/guitarist who had a significant impact on early psychedelia and jazz rock through co-founding The Byrds, and he also played a role in the dissemination of art rock into mainstream pop rock as part of Crosby, Stills and Nash (and Young). Most of Crosby's music is conventional enough that it doesn't sound arty but, for a brief period, he was at the forefront of the revolution.