Singer-songwriter-guitarist David Crosby, a founding member of two popular and extremely influential ’60s rock units, the Byrds and Crosby, Stills & Nash (later Crosby, Stills, Nash & Young), has died. He was 81 years old.

His wife released a statement to Variety, writing, “It is with great sadness after a long illness that our beloved David (Croz) Crosby has passed away. He was lovingly surrounded by his wife and soulmate Jan and son Django. Although he is no longer here with us, his humanity and kind soul will continue to guide and inspire us.”

The statement continues, “His legacy will continue to live on through his legendary music. Peace, love, and harmony to all who knew David and those he touched. We will miss him dearly. At this time, we respectfully and kindly ask for privacy as we grieve and try to deal with our profound loss. Thank you for the love and prayers.”

David Crosby was born in Los Angeles. In 1964, he founded The Byrds, who found their number-one hit in 1965, thanks to their cover of Bob Dylan’s “Mr. Tambourine Man.” In 1968, he founded Crosby, Stills, & Nash with Graham Nash and Stephen Stills. The group won a Grammy for Best New Artist in 1969.

While never the principal songwriter in the Byrds or CSN&Y, Crosby was an integral part of the densely layered harmony front line that launched both of those acts’ multiple chart hits. The hedonistic personification of the ’60s sex-drugs-and-rock ‘n’ roll lifestyle, he grappled with addiction for many years.

His sensational 1982 arrest in Texas on drug and weapons charges led to a five-month prison stay in 1986. Wracked by years of cocaine and alcohol abuse, he underwent liver transplant surgery in 1994. Though he never returned to the popular eminence of his early years, Crosby recorded and toured profitably into the 2000s.

Crosby, Stills, Nash & Young reunited for a performance at Farm Aid in 1985. In 1986, they appeared for the first of seven times as headliners at the Bridge School Concert, a benefit event organized by Neil Young and his then-wife Pegi for a Northern California school serving disabled children. He was inducted into the Rock and Roll Hall of Fame twice, as a member of the Byrds (1991) and Crosby, Stills & Nash (1997).

Crosby maintained his solo career with the albums “Oh Yes I Can” and “Thousand Roads.” His most unusual collaborative effort, the drolly named CPR, was founded in 1996 after he reunited with his son, pianist James Raymond, who had been born in 1962 and given up for adoption by his mother after a brief relationship with Crosby. The band, including guitarist Jeff Pevar, released four independent albums from 1998-2001. Crosby and Nash cut a self-titled duo released in 2004. His last solo recording, “Croz,” was issued in 2014. Crosby also had a career as an actor, appearing on “The John Larroquette Show” and “Roseanne.”

Crosby is survived by his wife Jan Dance, their son Django, son James Raymond, and two daughters, Erika and Donovan, from previous relationships.