David Crosby on stage in 2018 (Getty Images)

US folk-rock star David Crosby has died aged 81, his representative has confirmed.

In the 1960s, he was instrumental in the formation of two major bands: The Byrds and Crosby, Stills, and Nash. He was well-known for his guitar skills and vocal harmonies.

During his career, he accomplished the rare feat of being inducted into the Rock and Roll Hall of Fame twice.

Former bandmates praised Crosby's creative abilities while acknowledging the difficulties they had faced.

Crosby's wife told showbiz site Variety that he died "after a long illness" while surrounded by family.
"His legacy will continue to live on through his legendary music," her statement added.

He was born on August 14, 1941, in California, the son of Oscar-winning Hollywood cinematographer Floyd Crosby.

Trip down memory lane

Crosby joined The Byrds in 1964, a folk-rock band whose first hit was a cover of Bob Dylan's Tambourine Manو and whose other singles such as Turn! Turn! Turn! and Eight Miles High helped change the face of American pop and rock.

His turbulent tenure, which included a brief romance with singer Joni Mitchell, ended with his dismissal from the group three years later.

Crosby then formed a supergroup with Stephen Stills of Buffalo Springfield and Graham Nash of The Hollies, who were later joined by Neil Young of Buffalo Springfield.

This band, too, was plagued by infighting and disbanded after a few years, though they have reformed for concerts on occasion since.

Crosby's hits included the hippy anthems Almost Cut My Hair and Deja Vu, and he responded to Robert F. Kennedy's assassination in 1968 with the song Long Time Coming.

He became well-known for his countercultural politics, trademark mustache, and musicianship. His six-decade career culminated in the release of his final album, For Free, in 2021.

Crosby had several run-ins with US law enforcement off the stage, including an arrest in 1982 on drug and weapons charges.

His substance abuse was said to have worsened after the death of a girlfriend in a car accident when he was a young man.