The close, high harmonies and soft-rock songs of David Crosby, Stephen Stills, and Graham Nash as Crosby, Stills, & Nash—or CSN&Y, with the frequent addition of Neil Young —sold millions of albums and were widely imitated throughout the Seventies. The members were as volatile as their songs were dulcet, and since 1970 have continually split up and regrouped.

Rock’s first supergroup, Crosby, Stills, Nash, and Young each had successful recording careers before coming together—Crosby with the Byrds, Stills and Young with Buffalo Springfield, and Nash with the Hollies—and each has been inducted into the Rock and Roll Hall of Fame at least twice.

Stills and Crosby began writing songs together in 1968, after Buffalo Springfield broke up (The Byrds had already split, in 1967). Nash, who had just quit the Hollies, joined them soon thereafter and the trio performed together for the first time at the L.A. home of Cass Elliot of the Mamas and the Papas.

Recorded early in 1969, Crosby, Stills and Nash was an immediate hit, with singles “Marrakesh Express” (Number 28) and Stills’ “Suite: Judy Blue Eyes” (Number 21) (about Judy Collins). At the helm was Stills, playing nearly every instrument on the album, a feat that earned him the nickname Captain Manyhands. Young joined the trio in the summer of 1969—after John Sebastian, formerly of the Lovin’ Spoonful, turned them down—and Crosby, Stills, Nash & Young began touring. Their second live performance was in front of half a million people at Woodstock.

The quartet’s first album, Déjà Vu, took just two months to make and had advance orders for 2 million copies—it eventually went on to sell over 7 million—and included three hit singles: “Woodstock” (Number 11, 1970), “Teach Your Children” (Number 16, 1970), and “Our House” (Number 30, 1970). A few weeks after Déjà Vu’s release, the National Guard shot and killed four students during an antiwar demonstration at Kent State University. In response, Young wrote “Ohio,” which the group recorded and released as a single (Number 14, 1970). They toured that summer, but by the time the double live album Four Way Street was released, they had disbanded. The planned next album, Human Highway, was started in 1973 but was left unfinished. Young later recorded a single and produced a motion picture of the same title. Released in 1982, it failed to find a distributor, but came out on video in 1995.

Crosby and Nash released solo and duo albums in the early ’70s and toured together, while Young returned to his solo career, and Stills started his. Stills’ solo debut, which included “Love the One You’re With” (Number 4, 1971), featured guest guitarists Eric Clapton and Jimi Hendrix. In 1974, the quartet toured together for the first time since 1970, although tensions remained high: Young traveled separately. Stills and Young made a duet album, Long May You Run, in 1976, but Young suddenly left Stills mid-tour.

In 1977 Crosby, Stills and Nash regrouped for the quadruple-platinum CSN, which included “Just a Song Before I Go” (Number 7, 1977). The next summer they toured as an acoustic trio, and in the fall of 1979 they performed at the antinuclear benefit concerts sponsored by Musicians United for Safe Energy (MUSE). In 1982 the trio released Daylight Again, for which Stills wrote most of the songs, and toured arenas once more. Daylight was a Top-Ten LP and boasted two Top 20 singles, “Wasted on the Way” (Number 9) and “Southern Cross” (Number 18).

In 1985 Crosby—who’d already had a number of run-ins with the law and been charged with drug and weapons possession—was sentenced to prison for nine months after leaving the drug rehabilitation program he was allowed to enter instead of serving a five-year prison sentence for possessing cocaine and carrying a gun. He appeared with Stills, Nash and Young at Live Aid while out on appeal bond. Shortly after his release from prison in 1986, he wrote a compelling account of his long-term drug abuse entitled Long Time Gone, which was published in 1990. The four reunited to record American Dream (Number 16, 1989), after which Young refused to tour with his ex-band mates. Crosby, Stills, and Nash reconvened as a trio for 1990’s Live It Up (Number 58).

By the 1990s, Young was a hugely respected elder statesman of rock. Nash had been successful as a photographer with Nash Editions, specializing in digital fine-art printing, and as a host of his own cable television talk show. Crosby had received a liver transplant in 1994 shortly after CSN’s After the Storm (Number 98). In 1995 he reunited with a son, James Raymond, whom the child’s mother had given up for adoption in 1962. David and Raymond have recorded three albums as CPR. By the decade’s end, Crosby had also achieved notoriety as the sperm donor for celebrity lesbian mothers Melissa Etheridge and Julie Cypher.

In 1999, largely at the instigation of Stephen Stills, CSN&Y re-formed to record Looking Forward (Number 26). Earlier that year, Nash had broken both legs in a boating accident, but the group’s spirits and creativity were sufficiently high for the album to garner critical praise. It was followed by the band’s first tour since 1974, a heavily hyped cross-country trek entitled the CSNY2K Tour that featured studio veteran Jim Keltner on drums and Donald “Duck” Dunn of Booker T. and the MG’s on bass.

The quartet re-grouped once again in 2006 for the “Freedom of Speech” tour to promote Young’s new album, Living With War (Number 15).