The Roots: Phrenology

Not since the late-'80s heyday of the Bomb Squad has a rap group cared as much about the sound of their music as the Roots. This attention to detail is something that rock artists just take for granted; you're supposed to slave over the guitar's reverb or the lingering trail of a cymbal shimmer. If you think the Roots' attention to auditory detail seems anal-retentive, compare a random song from Phrenology with, say, any of the 25 tracks from Jay-Z's The Blueprint 2: The difference between making music and making beats is immediately obvious. For example, one of the album's early songs, "Sacrifice," slides in on tap-dancing high-hats and adds each element patiently and subtly--conga slaps, chicken-scratch guitars, a choral harmony--until Black Thought's familiar, raspy voice jumps into the fray. Dissect the song and no one element seems that remarkable, but pull everything together and "Sacrifice" weaves a texture you can't help wrapping your ears in.

On Phrenology's first half, every song feels like an epochal leap forward in sonic evolution--especially when the frantic b-boy breaks of "Thought @ Work" give way to "The Seed (2.0)," which pairs the band with rocker Cody Chestnutt for one of the best songs of the Roots' career. The whole song is nothing more than guitar, bass, and drums, but the Roots and Chestnutt fill it, brimming with a synergy of verve and joy.

Not surprisingly, the weakest songs on the album are also the most conventional. Tracks like "Quills," "Pussy Galore," and "Complexity" hark back to the Roots' traditional jazz/rap fusion and are pleasant but instantly forgettable. Despite the way the album builds during the first half-hour, its momentum shatters with the sloggy ballad "Break You Off." It never recovers, despite the ambitious brilliance of their 10-minute epic "Water," which is as much a journey as it is a song.

This unevenness hurts Phrenology's overall cohesion, but it shouldn't prevent it from earning its due. You've never really heard a hip-hop album like Phrenology before: It not only sounds different, it encourages you to listen differently.