The Isley Brothers founder Rudolph Isley has died. 

According to TMZ, the musician passed away on Oct. 11 in Illinois. His cause of death has yet to be determined, although a source told the outlet that he possibly suffered a heart attack. 

Rudolph and his brothers Ronald 82, and O’Kelly formed their R&B group in the late 1950s and enjoyed massive success with tunes such as “Twist & Shout,” “This Old Heart of Mine,” and “It’s Your Thing.”

In 1971, the group would expand, adding their younger brothers Marvin and Ernie, and Chris Jasper, Rudolph’s brother-in-law.

Rudolph departed from the band in 1989 to become a pastor, however, he has appeared alongside his old troupe over the years.