Trivia

Ex-bassist of the heavy metal band Metallica.

Replaced original Metallica bassist Cliff Burton in 1986 after Burton was tragically killed in a tour bus accident when Metallica's bus crashed in Sweden while they were touring Europe.

(October 9, 2002) Joins Canadian metal group Voivod as their permanent bassist, gets a new moniker from the band ("Jasonic") and makes his debut on their 13th studio album "The Multiverse" due to be released on 4 March 2003 (Jason's 40th Birthday).

He played with Flotsam and Jetsam from 1983 to 1986.

Replaced by Robert Trujillo in Metallica.

During his early days in Metallica, the rest of the band hazed him as a way to cope with the loss of Cliff Burton.

His nephew Michael is a very talented up-and-coming Christian musician.

On March 17, 2003, he was showcased as the newest member of Ozzy Osbourne's band. However, he remains with the legendary metal act Voivod and appeared on their self-titled 2003 album as well as their latest album due out in 2005. His relationship as friend and part time collaborator goes back almost 20 years and he has contributed to their music before, notably on the song "M-Body" for the album Phobos.

Participated in Rock Star Supernova, a supergroup created through the reality television series, Rock Star: Supernova.

Officially leaves Metallica after being in the band for 14 years. (January 2001)

Jason joined the band Supernova that is seeking a singer for the new band. The other band members are Gilby Clarke (guitar), and Tommy Lee (drums). The band selected Lukas Rossi to be their lead singer on September 13, 2006 on the television show Rock Star: Supernova. (July 2006)

Currently touring on the Ozzfest tour playing Bass with Ozzy Osbourne and Voivod. (August 2003)

Despite his departure from Metallica, he still keep sin contact with the band members.