Founding member of the Allman Brothers Band Butch Trucks has reportedly passed away at the age of 69. Trucks’ cousin Lee confirmed the news on Facebook and Chesapeake Bay Blues Festival also announced his passing. Trucks was scheduled to perform at the festival. A cause of death is currently unknown.

Born Claude Hudson Trucks—nephew of Major League Baseball pitcher and coach “Fire” Virgil Trucks—the drummer has been a cornerstone of the improvisational music community for nearly 50 years. Trucks grew up in Jacksonville, FL and first made his name playing in the area bands The Vikings and The 31st of February, the latter of which included future Cowboy principal Scott Boyer. Duane and Gregg Allman saw The 31st of February and invited Trucks to sit in with one of their early projects, The Allman Joys. Along with the Allmans, guitarist Dickey Betts, bassist Berry Oakley and drummer Jai Johanny “Jaimoe” Johanson, Trucks co-founded The Allman Brothers Band in 1969. The group quickly emerged as one of the architects of improvisational rock music and inspired a generation of blues and country-based Southern-rock groups. Trucks and Jaimoe helped popularize the double-drummer format, with Trucks holding the beat and Jaimoe providing the jazzy flourishes.

With the exception of Gregg Allman, Trucks was the group’s only constant in the band until their disbandment in 2014. During one of the Allmans’ breaks in the 1989s, Trucks formed the short-lived ABB spinoff BHLT with Dickey Betts, Jimmy Hall, Chuck Leavell, David Goldflies and Dan Parks. He participated in ensemble’s 1986 reunion and remained one of the group’s core members when they reunited in 1989. In the 1990s, he helped introduced the music world to his nephew, guitar protege Derek Trucks, he started sitting in with the Brothers when he was still a preteen and officially joined the band in 1999. Trucks also expanded the Allman Brothers’ percussion section to a trio with the addition of Marc Quinones in 1991; the drummer famously plucked him out of the jazz-fusion group Spyro Gyra after attending a gig.

Trucks emerged as a champion for the burgeoning jamband scene in the late ’90s, regularly attending shows and festivals that spotlighted emerging bands. He formed the supergroup Frogwings—which included, Quinones, Derek Trucks, Oteil Burbridge, Jimmy Herring, Kofi Burbridge and alternately Edwin McCain and John Popper—and formed the jam-friendly Flying Frog Record label. An entrepreneur, he also founded a streaming website and launched the Roots Rock Revival instructional summer camp in Upstate New York.

Especially after the Allman Brothers split with Dickey Betts, Trucks grew into one of the legendary band’s most visible offstage spokesmen and helped lead the band until their final performance in December of 2014. After the Allman Brothers retired, he continued to play with various projects including his Freight Train Band. Trucks also led the Les Brers project, featuring numerous ABB alumni and put together various Allman-related superjams at festivals like Wanee.

Trucks is survived by his artist wife Melinda Trucks, daughter and son Vaylor, who plays guitar with him in Freight Train. The drummer is also musically survived by nephews Derek and Duane Trucks, who lead the Tedeschi Trucks Band and play drums in Widespread Panic & Hard Working Americans, respectively.