Testament

Testament is an American thrash metal band from Berkeley, California. Formed in 1983 under the name Legacy, they are often credited as one of the most popular bands of the 1980s thrash metal scene. In the 31 years since its inception, Testament has had numerous lineup changes, and guitarist Eric Peterson has been the only constant member, although the band currently also features another one of its original members, Alex Skolnick (guitarist). Chuck 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.

source: Wikipedia