Testament is an American thrash metal band from Berkeley, California. Formed in 1983 under the name Legacy, the band's current lineup comprises guitarists Eric Peterson and Alex Skolnick, lead vocalist Chuck Billy, drummer Gene Hoglan, and bassist Steve Di Giorgio. In the 34 years since its inception, Testament has had numerous lineup changes, and Peterson has been the only constant member. Billy replaced former singer Steve Souza (who left the band to join Exodus as the replacement of Paul Baloff) in 1986, prior to the recording of their first studio album, The Legacy, and has been a member of the band since. Peterson and Billy are the only band members to appear on every album.
Testament is often credited as one of the most popular and influential bands of the thrash metal scene, having sold over 1.4 million albums in the United States since the beginning of the SoundScan era and over 14 million copies worldwide. To date, the band has released eleven studio albums, four live albums, six compilation albums, and six singles. After signing a recording contract with Atlantic Records in 1986, Testament's first five studio albums — The Legacy (1987), The New Order (1988), Practice What You Preach (1989), Souls of Black (1990) and The Ritual (1992) — were released to widespread critical acclaim. Shortly after the release of The Ritual, Skolnick and drummer Louie Clemente left the band and were replaced by James Murphy and John Tempesta on guitar and drums respectively. After one album with Murphy and Tempesta, and the departure of original bassist Greg Christian in 1996, Testament endured many lineup changes in the late 1990s and mid-2000s, leaving Peterson as the only remaining original member left. Since Skolnick's return to the band in 2005, Testament has undergone a resurgence in popularity, with their last two studio albums, Dark Roots of Earth (2012) and Brotherhood of the Snake (2016), peaking at higher chart positions in the United States.
During their major label years, Testament secured opening slots on major tours, including opening for notable acts such as Iron Maiden, Black Sabbath, Anthrax, Megadeth, Overkill, Judas Priest and Slayer. They also gained critical recognition for embarking on the European Clash of the Titans tour with Slayer, Megadeth and Suicidal Tendencies. To this day, the band continues to record and perform live.