Phil Lesh, co-founder and bassist of the Grateful Dead, died Friday at the age of 84.

Lesh’s death was announced on social media, with a short statement saying: “Phil Lesh, bassist and founder of the Grateful Dead, passed away peacefully this morning. He was surrounded by his family and full of love. Phil brought immense joy to everyone around him and leaves behind a legacy of music and love. We ask that you respect the privacy of the Lesh family at this time.” No cause of death was given.

From the time of the Dead’s first incarnation as the Warlocks, Lesh enjoyed an intimate three-decade partnership with lead guitarist Jerry Garcia. He also claimed responsibility for their tendencies toward long improvisation, electronic experimentation, and late-night free-form “space” interludes. After the group disbanded in 1995 due to Garcia’s death, Lesh became an active keeper of the live flame in both various configurations with former bandmates and in various iterations of Phil Lesh and Friends, including numerous guests from the expansive, multigenerational improvised band . -rock community.

Philip Chapman Lesh, the oldest member of The Dead, was born on March 15, 1940 in Berkeley, California. His father repaired office machines and his parents were co-owners of a repair company. Lesh played viola and trumpet at school, but gradually became more interested in composing than performing. He attended UC-Berkeley, where he befriended the even more musically adventurous Tom Constanten (who would play keyboards with the Dead for a while), but dropped out during his first semester. At Constanten he took a course with the great Italian avant-garde composer Luciano Berio at Mills College, where he met future minimalist figurehead Steve Reich, with whom he collaborated on a musical ‘happening’ called Event III/Coffee Break.

In 1959, Lesh met Garcia at a house party in the Bay Area to which, according to his 2005 memoir, he was referred “as if by an invisible hand.” When he met Lesh again after a 1964 performance by the Warlocks, Garcia invited him to join the band on bass guitar, an instrument Lesh had never played. Lesh played his first show with the Warlocks the following year at the Bikini A-Go-Go in Hayward, California. The renamed Grateful Dead became the house band for Ken Kesey’s infamous Acid Tests. An avid proponent of psychedelics as evidence of “a spiritual realm,” Lesh was deeply affected by these evenings that blurred the lines between band and audience.

The Grateful Dead played “electric chamber music,” according to Lesh, whose main influence as a bassist was Johann Sebastian Bach’s counterpoint style (the relationship of two independent but interdependent musical voices). When he wasn’t dropping his infamous “bass bombs,” he played his instrument as if it were a low guitar, usually with a pick, and often as a lead instrument. The 1960s became an era of intense musical experimentation for the group, most prominently on the band’s second album, Anthem of the Sunwhere Lesh suggested overdubbing different live versions of “The Other One” on top of each other and letting them drift apart. “I’m nostalgic for that psychedelic Ranger era when we played National Anthem live in its entirety,” he told Rolling Stone in 2014. “It was apocalyptic – every time.”

“Box of Rain” and “Unbroken Chain” were warm psychedelic masterpieces among the handful of songs Lesh co-wrote for the Dead. He contributed the high parts to the four-part harmonies that the band mastered Worker is dead And American beautybut ultimately left the singing to others, despite occasional chants from the audience to ‘let Phil sing’. In 1975 he played electronically processed bass on electronic musician Ned Lagin’s abstract Sea stones.

Although touring had lost its appeal, Lesh continued with the Dead through the increasingly troubled 1980s, when drug problems rocked the band, and then into the 1990s, ending with Garcia’s death. “Jerry was the lynchpin,” he said Rolling stone. “We were the spokespersons. And the music was the tread on the steering wheel.”

In 1998, Lesh received a liver transplant due to the hepatitis C he had contracted decades earlier. The procedure led to him becoming a passionate advocate for organ donors. He survived prostate cancer in 2006.

A one-off 1994 acoustic show featuring some Grateful Dead members was billed as Phil Lesh and Friends, a name he would use for the rest of his career for performances with an ever-changing musical cast. The group’s 1999 post-Dead debut featured Trey Anastasio and Phish’s Page McConnell. Lesh also released three albums of jammy rock under the name. During the Aughts, Lesh sometimes rejoined his former bandmates in Grateful Dead repertoire formations such as The Other Ones, The Dead and Furthur, which also featured Bob Weir. In 2005, Lesh published his memoirs In Search of the Sound: My Life with the Grateful Dead.

Lesh’s wife, Jill, whom he married in 1984, became a close partner in all aspects of his life. In 2012, the Leshes opened Terrapin Crossroads, restaurant and venue, in San Rafael, California. Their sons, Grahame and Brian, serve as the house band, and the bassist himself was known to sometimes back up nights of live Dead karaoke.

Lesh and the rest of the Dead were celebrating their 50th anniversary^e anniversary in 2015 with a series of “Fare Thee Well” shows in Chicago, together with Anastasio. That year, Lesh revealed he had contracted bladder cancer. “I’m one of those guys who’s always open,” he said in 2013. “You see, music is infinite. There’s an infinite number of ways to do it, an infinite number of melodies that can have a one-four-five progression, it’s absolutely infinite, no floors, no ceiling.