Jason Curtis Newsted (born March 4, 1963) is an American metal musician, known for playing bass guitar with the bands Metallica (in which he did occasional lead vocals), Voivod and Flotsam and Jetsam. Joining Metallica in 1986 after Cliff Burton's death, Newsted remained a member until 2001, making him the band's longest-serving bassist. After he left Metallica, he continued with his project Echobrain, played with Ozzy Osbourne and joined heavy metal band Voivod. Newsted uses the pseudonym Jasonic, which serves as both his alias in Voivod and the name of his music publishing company. He is also the founder of the Chophouse Records studio and label based in California. He currently plays in his self-titled band Newsted, in which he provides lead vocals as well as bass.