Isis

Isis

Ambient metal? No telling what that means, unless you were privy to Isis' 2002 breathtaker Oceanic. To put it differently, Isis is Mogwai gone doom metal, Sigur Rós gone black metal. Panopticon, like its predecessor, is as deep and meditative as Kant, as overwhelmingly voluminous as Niagara Falls. The difference is Panopticon is both more gentle than Oceanic and more extroverted. Aaron Turner's Sauron-from-a-mountaintop vox emote more forcefully than ever on "Backlit," which resurrects the ghosts of Tool and A Perfect Circle, only with real elegance. The album's midsection is a harrowing journey down dark, stygian rivers, both placid and ominous. "In Fiction" rises up out of the dark tapestry of sound and overwhelms with molten low-end High on Fire riffage. "Altered Course" is a masterfully constructed glacial flow, with Aaron Harris' heavy drumming keeping the mast pointed through the crushing turbulence that's part-and-parcel of this Boston troupe's revelatory existence. Panopticon may not reach the heights or descend to the depths of Oceanic, but it's an amazing journey to a place unlike any other. (Isis plays Emo's Tuesday, Dec. 14.)