E-Mail This Article to a Friend Thinking person’s metal (continued)

In the two years since Isis last had a new CD out, metal has exploded at MTV thanks to the revival of Headbangers Ball. The hype has even managed to trickle down to more experimental bands like Mastodon, with whom Isis share producer Matt Bayles and a general spirit of adventure. Although intrigued by the potential for increased exposure without compromise, Turner maintains a healthy skepticism about his own commercial prospects. "A lot of bands are straddling the line between the underground and the mainstream. There’s almost like this nebulous, in-between world now. We’ve gained a larger audience in the last couple years, but to keep going that way? I don’t know. I still feel like there are certain elements of our band that are going to be hard for people with mainstream tastes to accept. We don’t have the crossover potential of Shadows Fall. The biggest concern for us is being able to make albums the way we want to. Everything else is a bonus."

Any Isis fan can rattle off, with glee, the "certain elements" Turner’s talking about: no choruses, gruff vocals, and plenty of what most metalheads consider "noise." The paranoia and angst that go along with the Panopticon theme are apparent on "So Did We," which opens the disc with a growl from Turner and the band’s trademark sledgehammer attack. But they take it down a notch as the song progresses, introducing pretty acoustic guitar and keyboard melodies into the mix.

That contrast sets the tone for the rest of Panopticon. The biggest surprise here is "Backlit," which cuts through the doom with the most serene chords to hit avant-rock since the last Lightning Bolt album. Guitarists Turner and Mike Gallagher also make a handful of references to early U2 with the echoing melodies they bring to the mix. Utility player Cliff Meyer contributes more keyboard than usual, his moody hooks stepping to the forefront in the disc’s quieter moments. And the rhythm section’s mastery of dynamics remains something few of their peers can match.

Along with the "In Fiction" video, Isis have increased their mainstream visibility by collaborating with Tool’s Justin Chancellor, who’s credited with "additional sounds/bass" on "Altered Course." The longest track on the album at almost 10 minutes, the atmospheric jam would not have sounded out of place on Tool’s Lateralus (Volcano). Opening with an imposing cathedral of guitars, it hits a crest of fuzztone grandeur before decaying into a blanket of quiet static. "Grinning Mouths" follows, closing the disc with a flurry of aggression and some vocal anguish from Turner. Like its predecessor, this is a well-executed concept album that shimmers as much as it pummels.

DIECAST WERE ONE OF THE MANY BANDS Isis shared bills with in the late 1990s, during the Headbangers Ball–free era that served as an incubation period for Boston metalcore. Led by bassist Jeremy Wooden and drummer Jason Costa, Diecast have always been one of the more commercial outfits on the regional scene, combining unfettered aggression straight out of the Hatebreed school of hard knocks with an occasional knack for big rock hooks. Their 2001 anthem "Singled Out" sounded like the second coming of Slipknot, but since then, things haven’t been easy for them: their label, Now or Never, went out of business, and frontman Colin Schleifer left the band. But they regrouped with new singer Paul Stoddard to record Tearing Down Your Blue Skies for the hot label Century Media (Shadows Fall). Last week, Diecast played a trio of New England shows opening for E.Town Concrete.

The first single from the disc is "Medieval," for which the band just shot a performance video with director Dale Resteghini (Unearth). As in plenty of other metal songs these days, the chorus can be read as an anti-war statement: "Loose cannons fire as they target shades of gray/Never mind a mind that never evolves from the medieval." The group indulge both sides of their personality on the track, shifting between Converge-style blitzkrieg dissonance and radio-ready tunefulness. Despite the commercial sheen of the production, the arrangement is a tricky one that doesn’t pander to the mainstream: the chorus opens and closes the song, but the rest abandons melody in favor of fury.

On Tearing Down Your Blue Skies, the Diecast formula continues to work better in practice than it does in theory — they make crushing breakdowns and bar-rock sing-alongs sound as if they were meant to be together. The disc opens with a bang, as a tender guitar melody gives way to a Slayer-inspired drum conniption. On that song, "Fire/Damage," Stoddard laments war as he tries to "read between the burning towers." "Savior" makes up for its misuse of the language with one of the band’s best choruses: "Your prayer infuriates my anger, so I will find my savior/Right or wrong, I’m on my own, I will stand so strong." That track also reveals that the "blue skies" in the album title belong to one of metal’s most time-tested enemies: self-righteous moralists. The group address the inner turmoil of the last few years on "Rebirth," which ends the album with a tasty twin-guitar requiem. It’s a heavy reminder that Diecast are still one of the scene’s most original acts.

Isis perform this Friday, December 3, downstairs at the Middle East, 480 Massachusetts Avenue in Central Square; call (617) 864-3278.