Testament is an American thrash metal band from Berkeley, California. Formed in 1983 under the name Legacy, the band consists of vocalist Chuck Billy, guitarists Eric Peterson and Alex Skolnick, bassist Steve DiGiorgio and drummer Gene Hoglan. In the years since its inception, Testament has had numerous lineup changes, and Peterson has been the only constant member. Billy replaced former singer Steve Souza in 1986, prior to the recording of their first studio album, The Legacy, and has been a member of the band since. Billy and Peterson are the only band members to appear on every album.