Phil Lesh, a founding member of the Grateful Dead whose nuanced bass playing made him an architect of the band’s otherworldly sound, died on Friday at age 84, his Instagram account said.

Tributes poured in from the music world and New York’s Empire State Building said it would illuminate the skyscraper in tie-dye colors to honor a member of the psychedelic band known for lengthy improvisations in its live shows, which drew dedicated “Dead Head” fans known for traveling from concert to concert.

The Instagram post said he died peacefully, surrounded by family.

Rolling Stone magazine ranked Lesh as the 11th greatest bass player of all time, though he also sang lead and backing vocals. Many fans considered him as influential as the band’s front man, Jerry Garcia, who died in 1995.

“His idea - ‘play bass and lead at the same time,’ his notes darting in and around the melody - became as recognizable a part of the Dead’s sound as Garcia’s guitar,” Rolling Stone said.

“Phil was more than a revolutionary, groundbreaking bass player - he transformed how I thought about music as a teenager,” Trey Anastasio, the lead guitarist of Phish, wrote on Instagram.

Formed in California in 1965, the Dead came to prominence during the 1967 Summer of Love in San Francisco, a counterculture movement that embraced peace, love and hallucinogenic drugs.

But the Dead’s music endured much longer than that as a mixture of rock, folk, country and jazz.

After Garcia’s death, longtime players Bob Weir, Bill Kreutzmann and Mickey Hart formed various lineups under the name Dead & Company, while Lesh opted instead to create Phil Lesh and Friends, which played until 2023.

Philip Chapman Lesh was born on March 15, 1940, in Berkeley, California, and began playing classical violin before switching to “cool jazz” big-band trumpet, his official Dead biography said.

He later studied with experimental Italian composer Luciano Berio before his friend Garcia told him in 1965 that he was the new bass player for the Warlocks, Garcia’s band that was a precursor to the Grateful Dead.

Lesh responded, “Why not?”

Lesh is survived by his wife, Jill Lesh, and their two sons, Grahame and Brian.