Testament and Anthrax co-headline a tour that stops at Lifestyle Communities Pavilion Friday, Feb. 3. Tickets are $27.50/$29. Visit www.promowestlive.com.

That Chuck Billy's band is still around wreaking havoc on audience members who've been around for 25 years and those who've come around because of its influence on younger bands is a, um… testament to his commitment to metal excellence. Testament had not yet released its first record when Billy joined the band in 1985, so essentially, he is the band's original frontman. In the years since, he has helped navigate the band through the waxing and waning of thrash metal, numerous personnel changes and his own battle with cancer. "Of course, you think you could do this forever, but the truth is, forever isn't even something you think about" when you start out, Billy told The Beat. "You just have this group and you're trying to make it a success." Which Testament was in the late '80s and early '90s - not coincidentally the high-water mark for thrash metal itself. While music historians place Testament just outside thrash's "Big Four" of Metallica, Megadeth, Slayer and Anthrax, records like Testament's The New Order, Practice What You Preach and Souls of Black are staples of the sub-genre. The departure of gifted guitarist Alex Skolnick in 1993 began a series over the next five to10 years of comings-and-goings and a recommitment to full-on thrash-style playing. (Skolnick, who wanted to play more melodic material, formed a jazz trio and also played with prog-metal band Savatage, which eventually became the foundation of Trans-Siberian Orchestra.) "We had a revolving door of musicians," Billy said. "It really does make a difference." In 2001, Billy was diagnosed with a rare form of cancer, for which he sought treatment and fully recovered over a three-year period. (Today, Billy said, he has annual check-ups and remains cancer-free.) In the late 2000s, the band's "classic" lineup reunited, with Skolnick, bassist Greg Christian and drummer Louis Clemente joining Billy and guitarist Eric Peterson. "It's been a sense of 'finish what you started,'" Billy explained. "There's a level of confidence we have in each other, and it's only grown as Alex has come around to the songs from after he left." Testament finished recording a new album just two weeks ago (to be released later this year), its second since the "reunion" (Clemente's spot on drums in being manned by past Testament drummer Paul Bostaph and others). "I was really pushed vocally on this record, which I'm excited about. I'm singing better than ever, I think, but had gotten comfortable with what I knew," Billy said. "It's always stressful and we're glad to be done and get back on tour." Touring with old friends Anthrax is "like riding a bike," he said, "picking right up where we left off." Riding out the changes in his own band and changes in musical tastes over the past 25 years is something of which Billy is proud. "A lot of bands called it quits, but we've survived a lot of changes and kept doing what we do," he said. "And if you think about it, we've lived through all that stuff we sang about 20 years ago, and come out the other side."