Veteran rock musician Bob Weir, the Grateful Dead's rhythm guitarist who helped guide the legendary jam band through decades of change and success, has died at age 78, according to a statement posted to his verified Instagram account on Saturday.

He was diagnosed with cancer in July and "succumbed to underlying lung issues" surrounded by loved ones, the statement said. It did not mention when or where he died.

Along with his late fellow Grateful Dead co-founder and lead guitarist Jerry Garcia, who was at the center of the Deadhead universe, Weir was one of the group's two frontmen and main vocalists for most of the band's history.

It was Weir who sang the verses on the band's trademark boogie anthem, "Truckin'," and who wrote such key songs as "Sugar Magnolia," "Playing in the Band" and "Jack Straw."

The youthful, ponytailed "Bobby" grew into an eclectic songwriter whose handsome appearance and diverse musical influences helped broaden the band's appeal. British newspaper The Independent called Weir "arguably rock's greatest, if most eccentric, rhythm guitarist."

After Garcia's death at age 53 in 1995, Weir carved out an interesting if somewhat neglected solo career - much of it with his band, RatDog - and participated in reunions of surviving Dead members in different configurations.

LONG STRANGE TRIP

"As the one good-looking guy in the Dead, baby-faced Weir was always what passed for the band's sex symbol," the San Francisco Chronicle's Joel Selvin wrote in 2004. "He didn't care about that, either. In fact, he always seemed to secretly relish subverting that image."

Weir was the subject of the 2014 documentary "The Other One: The Long, Strange Trip of Bob Weir," which made a case for the Dead's "other" guitarist as a musical force. Though some diehard Dead fans, or "Deadheads," adopted the trappings of tie-dyed psychedelia, the group itself was deeply attached to American roots music and was credited with bringing experimental improvisation to rock music.

Weir's own musical tastes ranged from Chuck Berry to cowboy songs to R&B and reggae.
Thanks to relentless touring, constant musical evolution and a passionate fan base, the Grateful Dead - who existed from 1965 to 1995 - did not have to rely on producing hit records.

"Bob was the wild one," journalist Blair Jackson wrote in 2012. "He was the rock 'n' roller, but also the confident, smooth-voiced narrator on all those dramatic country-rock numbers about desperadoes and fugitives; a perfect fit for those tunes. He was the guy who would screech and scream himself hoarse at the end of the show, whipping us into a dancing frenzy."

Weir, whose birth name was Robert Hall Parber, was born on October 16, 1947, and raised by adoptive parents in Atherton, California. He did not excel in school, due in part to his undiagnosed dyslexia. In 1964 at age 16, he met Bay Area folk musician Garcia, with whom he formed the Warlocks, who soon morphed into the Grateful Dead.

THE KID

The athletic Weir, who enjoyed football, was the youngest member of the original band and was sometimes referred to as "the kid."

He was still in high school when he joined up with Garcia, bass guitarist Phil Lesh, organist-vocalist-harmonica player Ron "Pigpen" McKernan and drummer Bill Kreutzmann.

Lesh recalled in his 2005 autobiography that he and Garcia had to make a promise to young Bob's mother. "The long and short of it was that if Jerry and I promised to make sure that Bob got to school every day, and that he got home all right after the gigs, she would allow him to remain in the band," wrote Lesh, who died in October 2024 at age 84.

"We somehow convinced her that we would indeed see that he got to school every day. In San Francisco. At 8:00 a.m."

Eventually Weir moved in to the communal Dead house at 710 Ashbury Street in San Francisco. The group's first album, "The Grateful Dead," was released in March 1967.

According to some accounts, Weir was briefly fired from the band in 1968 because his guitar skills were deemed lacking. But he either redoubled his efforts or the others had second thoughts, because he was soon back in. By the time of the band's two famous 1970 albums, "Workingman's Dead" and "American Beauty," Weir was a key contributor.

His 1972 solo album, "Ace," was a de facto Grateful Dead album that featured Garcia and the others and included well-regarded Weir songs including "Cassidy," "Black-Throated Wind," "Mexicali Blues" and "Looks Like Rain." Many of his best-known songs were co-written with his old school friend, John Perry Barlow, who died in 2018.

As the band's rhythm guitarist, Weir often played little fills, riffs and figures instead of straight chords. "I derived a lot of what I do on guitar from listening to piano players," he told GQ magazine in 2019, citing McCoy Tyner's work with saxophonist John Coltrane. "He would constantly nudge and coax amazing stuff out of Coltrane."

Even decades after Garcia's death, Weir never forgot the influence of his old friend. He told GQ that Garcia was still present when Weir played guitar. "I can hear him: 'Don't go there. Don't go there,' or 'Go here. Go here,'" Weir said. "And either I listen or I don't, depending on how I'm feeling. But it's always 'How's old Jerry going to feel about this riff?' Sometimes I know he'd hate it. But he'd adjust."

In 2017, Weir was appointed as a United Nations Development Program goodwill ambassador to support the agency's work to end poverty while fighting climate change.
Weir married Natascha Muenter in 1999. They had two daughters.

"Looking back," Weir once said, "I guess I have lived an unusual life."