Nick Menza, former drummer for Megadeth, has died after collapsing on stage during a performance with his jazz trio.
Family spokesman J Marshall Craig said the star's latest band, OHM, was three songs into a set at a club in the LA area on Saturday night when the drummer collapsed.
Friends and audience members gave first aid while paramedics were called.
Megadeth frontman Dave Mustaine revealed his shock over the news.
Craig said the 51-year-old died at the club of a suspected heart attack.
Former band member Marty Friedman wrote on Facebook that he was "beyond sad" at the news.
Nick was Megadeth's longest-serving drummer, performing on five records over nine years, including 1990´s thrash metal landmark, Rust In Peace.
After leaving Megadeth in 1998, he pursued an interest in jazz and became an accomplished woodworker.
The drummer is survived by his parents and two sons.