Bob Matthews, the longtime sound engineer for the Grateful Dead, has passed away as confirmed on Saturday. Matthews worked alongside Betty Cantor-Jackson to record countless hours of live Grateful Dead concerts.

Originally a member of the pre-Dead Mother McCree’s Uptown Jug Champions, Matthews went on to play bass in New Riders Of The Purple Sage alongside Jerry Garcia, David Nelson, and more. Matthews can also be heard on a cover of “Accidentally Like A Martyr” on the Jerry Garcia box set, All Good Things.

But it’s not about what fans heard from Matthews that made him so prolific, but it was what he let fans hear from the Dead. In the wake of his passing, Bob Weir called Matthews “our first roadie – first employee, though his wages amounted to not much more than free entry & gas money to get himself & our gear to the gig.”

Matthews and Cantor-Jackson—known simply as the duo Bob & Betty, artists in their own rite—engineered numerous live Grateful Dead albums including Live/DeadEurope ’72Grateful Dead (aka Skull & Roses), and more. His work wasn’t just limited to live performances either, as he also contributed to Aoxomoxoa, Workingman’s Dead, Blues For AllahGarcia, Ace, and many more.

In 2004, Bob & Betty reunited for the first time in 25 years to record Dark Star Orchestra at San Francisco’s Fillmore Auditorium on May 8th, 2004, later released as Live at the Fillmore. Most recently, Matthews has been a vital piece of The Good Ol’ Grateful Deadcast, providing new historical context behind the Grateful Dead’s albums with hosts Rich Mahan and Jesse Jarnow.

“I always sought & valued his views on how the music & the band were developing,” Weir wrote on social media. “He went on to become our *recordist* – a word I hadn’t yet heard at that point & really haven’t heard since. In later years he went on to success in a telecommunications field I have yet to understand. The next world that awaits us all will be more efficient and sound better now. Bob Voyage, Vaya con Dios, Bob Matthews.”

RIP Bob Matthews.