Crosby, Stills & Nash (CSN) is a folk rock supergroup made up of David Crosby, Stephen Stills and Graham Nash, also known as Crosby, Stills, Nash & Young (CSNY) when joined by occasional fourth member Neil Young. They are noted for their intricate vocal harmonies, often tumultuous interpersonal relationships, political activism, and lasting influence on American music and culture. All four members of CSNY have been inducted into the Rock and Roll Hall of Fame twice, though Young's inductions were for work not involving the group.Prior to the formation of CSN, each member of the band had belonged to another prominent group. David Crosby had performed rhythm guitar, vocals and songwriting with folk-rock group The Byrds; Stephen Stills had been a guitarist, vocalist and songwriter in the band Buffalo Springfield, which also featured Neil Young; and Graham Nash had been a guitarist, vocalist and songwriter with The Hollies, one of the "British Invasion" acts. Friction existed between David Crosby and his bandmates in the Byrds, and he was dismissed from the band in late 1967. By early 1968, Buffalo Springfield had also disintegrated over personal issues, and after aiding in putting together the band’s final album, Stephen Stills found himself unemployed by the summer. He and Crosby began meeting informally and jamming, and the result of one encounter in Florida on Crosby’s schooner was the song "Wooden Ships", composed in collaboration with another guest, Jefferson Airplane's Paul Kantner.