.Isis

These chin-scratching headbangers need a swift kick in the ass. Shimmering guitars like waves on a vast ocean? Check. Throbbing basslines? You bet. Vocals like a trapped bear’s howl? Oh yeah. Yet despite some very pretty organ work on “Holy Tears” and some occasional electronic trickery, In the Absence of Truth is recognizably an Isis album, from the slowly rising feedback that opens “Wrists of Kings” to the last jangling chord of the closing “Garden of Light.” So is it really necessary? To many ears, the band peaked with 2002’s Oceanic and its associated remixes; 2004’s Panopticon was monochromatic, and now the Boston quintet’s fourth full-length is its most sonically diverse album to date. But in the process of adding new facets to its sound, Truth winds up reinforcing self-imposed limitations. Isis’ music is not about catharsis, which is a big problem for metalheads or anybody else looking for a reason to get worked up. No matter how loud the guitars get, they always sway gently, never crashing or exploding. Isis has already toured with Tool; if it keeps pushing this stoic we’re-above-rocking-out shtick, it’ll be opening for Coldplay soon.