The first, and possibly only, folk rock supergroup, Crosby, Stills, Nash & Young are noted primarily for their intricate vocal harmonies, stunning compositions and often tumultuous interpersonal relationships. Political activism and an ongoing influence on American music and culture probably come reasonably close. All four members have been inducted into the Rock and Roll Hall of Fame twice, although Young's inductions were for work not involving the group. However, their body of work stands as testimony to a group whose main purpose has been ever successful.