The brash rock musician who evolved from a baby-faced harmony singer with the Byrds to a mustachioed hippie superstar and an ongoing troubadour in Crosby, Stills, Nash & (sometimes) Young, has died at 81, several media outlets reported Thursday.

The New York Times reported, based on a text message from Crosby’s sister in law, that the musician died Wednesday night. Several media outlets reported Crosby’s death citing anonymous sources; The Associated Press was unable to reach Crosby’s representatives and his widow.

Crosby underwent a liver transplant in 1994 after decades of drug use and survived diabetes, hepatitis C and heart surgery in his 70s.

While he only wrote a handful of widely known songs, the witty and ever opinionated Crosby was on the front lines of the cultural revolution of the ’60s and ’70s — whether triumphing with Stephen Stills, Graham Nash and Neil Young on stage at Woodstock, testifying on behalf of a hirsute generation in his anthem “Almost Cut My Hair” or mourning the assassination of Robert Kennedy in “Long Time Gone.”

He was a founder and focus of the Los Angeles rock music community from which such performers as the Eagles and Jackson Browne later emerged. He was a twinkly-eyed hippie patriarch, the inspiration for Dennis Hopper’s long-haired stoner in “Easy Rider.” He advocated for peace, but was an unrepentant loudmouth who practiced personal warfare and acknowledged that many of the musicians he worked with no longer spoke to him.