RatDog bassist Robin Sylvester has passed away, Relix confirmed. Former RatDog guitarist Mark Karan announced the news in a social media post, stating, “I can’t believe what I just heard. Our dear, sweet Robin Sylvester has passed & left us all with a big ol’ hole in our hearts…I’m speechless & gutted.” An official cause of death has not been made public at this time.

Born in London in 1950, Sylvester sang with the a cappella London Boy Singers chorus when he was young before going on to work in Abbey Road studios at the same time The Beatles were recording The White Album. He was a true multi-instrumentalist, experimenting with synthesizers and working as a guitarist and arranger, but was inspired by Paul McCartney and The Fab Four to focus on the bass.

In London, he backed actress/singer Dana Gillespie, and in 1974, he immigrated to the U.S. and signed to Clive Davis‘s Arista label with his folk outfit The Movies. He played alongside Marty Balin, The Coasters, The Drifters, Billy Preston, Christine McVie, Bo Diddley, Chuck Berry, and many more and worked in the studio with The Beach Boys and Ry Cooder.

He also played with Grateful Dead keyboardist Vince Welnick’s Missing Man Formation, which is what led him to join Bob Weir‘s RatDog in 2003 following the departure of founding bassist Rob Wasserman. He kept playing with RatDog even after Wasserman returned to the lineup years later and also collaborated with Dead-associated bands including Ghosts of Electricity, Melvin Seals & JGB, David Nelson & Friends, Jemimah Puddleduck, and The Rubber Souldiers.

Sylvester’s health issues became apparent to fans when he missed several shows in 2012 while awaiting a kidney transplant. He was hospitalized for months at a time several times in recent years. Sweet Relief has set up a fund to help cover his medical bills.

RatDog has been in inactive since 2014, though members of the band have collaborated for benefit concerts as recently as 2018. Bob Weir & Wolf Bros dedicated their show to Sylvester’s memory on the night of his passing.