Phil Lesh, the influential bassist of the Grateful Dead who powered many of the jam band’s touring incarnations after the 1995 death of Jerry Garcia, has died. He was 84.

Lesh’s death was announced on his Instagram page. “Phil Lesh, bassist and founding member of The Grateful Dead, passed peacefully this morning,” the caption reads. “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 request that you respect the Lesh family’s privacy at this time.”

Born on 15 March 1940 in Berkeley, California, Lesh was a student of classical music throughout childhood. A trained trumpet player, he studied with the avant garde composer Luciano Berio and played with minimalist composer Steve Reich. He switched to bass – an instrument he had never played – in 1965 after he was recruited by the Warlocks, a band fronted by his friend Garcia, for a show at a pizzeria in Menlo Park, California.

“I was so excited that I didn’t have to think about it … but I knew something great was happening, something bigger than everybody, bigger than me for sure,” Lesh told the Dead’s publicist and official historian Dennis McNally for the 2002 book A Long Strange Trip, according to Variety.

Lesh’s imprint was crucial on the early sound of the Grateful Dead, often credited alongside Garcia. He co-authored a number of compositions, including St Stephen, The Eleven and Dark Star, that became staples of the jam band’s repertoire. Between 1967 and 1990, Lesh appeared on all 13 of the Grateful Dead’s studio releases and 10 official live albums. Along with Garcia, guitarist Bob Weir and drummer Bill Kreutzmann, Lesh remained a vital part of the improvisational band’s touring lineup for 30 years.

After Garcia’s death in 1995 at the age of 53, Lesh was a staple of the band’s later touring arrangements, including the Other Ones (1998-1999), the Dead (2003-2004, 2008-2009) and Furthur (2009-2013). He sat out the band’s latest incarnation, Dead & Company, fronted by John Mayer.

Along with the other members of the Grateful Dead, Lesh was inducted into the Rock and Roll Hall of Fame in 1994. He is survived by his wife, Jill, and their sons, Grahame and Brian, both of whom performed with the Terrapin Family Band, Lesh’s late-in-life band formed through his family-operated music hall and restaurant in San Rafael, California.