In the decades since Slayer's inception in 1982, although the band have messed about with various techniques and sounds -- they even cut a disastrous nu-metal album -- they've never really been big on experimentation. Of the big four -- with Metallica, Anthrax and Megadeth -- they've remained closer to their roots than any of the others. Repentless, their debut for Nuclear Blast, is their first record in six years and showcases a host of changes. The most significant one, of course, is the death of founding guitarist Jeff Hanneman in 2013 -- the chief architect of the band's sound. As the composer of many classic Slayer tracks including "Hell Awaits," "Angel of Death," "Dead Skin Mask," "Raining Blood," etc., he brought an unhinged punk spirit and inventive creative intuition to Slayer's metal palette. It contrasted sharply with fellow guitarist Kerry King's thrash approach and carved out a signature sound. Gary Holt of Exodus was selected as Hanneman's replacement, but his approach is closer to King's, making new songs less distinct. Repentless also marks the return of drummer Paul Bostaph after the controversial firing of Dave Lombardo. If Slayer ever needed a reason to look back for inspiration, it's here. The lion's share of responsibility for their sound has been passed on to King. He is not as imaginative as Hanneman, but does a more than acceptable job. This is mostly a thrash metal offering, full of manic tempos, blistering riffs, naked aggression, typical misanthropy, and angry grief (check "Chasing Death" as proof of the latter). The title track single attempts to mirror the band's earliest attack and mostly succeeds. "Take Control" is an anthemic call to warfare with Araya in grainy but still ferocious voice. Fine breaks by King and Holt elevate it to choice cut status. "Vices" is a crushing paean to violence ("...It's a rush you can't deny/a little violence is the ultimate drug/let's get high!…") emphasized by a blistering solo from King. Hanneman has a writing credit on "Piano Wire," partially composed at the time of his death. It offers a chugging, grooving riff and a couple of sharp tempo changes. Bostaph's drumming is solid. He's quick, technical and physical -- listen to the alternating double bass and hi-hat work on "Cast the First Stone." "When the Stillness Comes," an outlier in the middle of the record, commences with doom and mystery as Araya whispers atop a moody guitar and cymbals. While it shifts to crunchy, midtempo riffing, it doesn't go anywhere -- it's just album filler. That's compensated for by the insane pace and guitar soloing in "You Against You." Repentless is a retro, workmanlike effort from a band determined to soldier on, and that's fine. There are hardcore devotees who never want their favorite bands to change; this is for them. But again, given all that's transpired since 2009, Slayer get points for even pulling this off.