Louis Johnson, Brothers Johnson bassist and key Michael Jackson collaborator, died Thursday, May 21, at the age of 60. His nephew, Troy, confirmed the musician's death via Instagram and to Rolling Stone. Johnson's cause of death has yet to be reported.

Louis Johnson is well known for his multiple collaborations with the King of Pop. He played bass riffs on Jackson's Off the Wall and Thriller albums and is credited for his work on "Billie Jean," "Wanna Be Startin' Somethin'" and "P.Y.T."
"I've never been given parts to play in my whole life. I'm the most rare bass player in the whole world," Johnson told Rolling Stone in 2013 for the book MJ: The Genius of Michael Jackson. "No one ever gave me music paper to read; no one ever gave me anything to read. They tell me, 'Here's a track, play what you want.'"

Producer Quincy Jones -- who worked with Brothers Johnson in the mid-'70s and '80s and produced their first album -- expressed shock and sadness on social media Friday.

"Louis 'Thunderthumbs' Johnson was one of the greatest bass players to ever pick up the instrument," he wrote in a statement posted on Facebook. "As a member of the Brothers Johnson we shared decades of magical times working together in the studio and touring the world."