The easy-flowing Things Fall Apart made the Roots one of the most popular artists of alternative rap's second wave. Anticipated nearly as much as it was delayed, the proper studio follow-up, Phrenology, finally appeared in late 2002, after much perfectionist tinkering by the band — so much that the liner notes include recording dates (covering a span of two years) and, sometimes, histories for the individual tracks. Coffeehouse music programmers beware: Phrenology is not Things Fall Apart redux; it's a challenging, hugely ambitious opus that's by turns brilliant and bewildering, as it strains to push the very sound of hip-hop into the future. Despite a few gentler tracks (like the Nelly Furtado and Jill Scott guest spots), Phrenology is the hardest-hitting Roots album to date, partly because it's their most successful attempt to re-create their concert punch in the studio. ?uestlove's drums positively boom out of the speakers on the Talib Kweli duet "Rolling With Heat"; the fantastic, lean guitar groover "The Seed (2.0)" (with neo-soul auteur Cody ChesnuTT); and the opening section of "Water." The ten-minute "Water" is the album's centerpiece, a powerful look at former Roots MC Malik B.'s drug problems that morphs into a downright avant-garde sound collage. Similarly, lead single "Break You Off," a neo-soul duet with Musiq, winds up in a melange of drum'n'bass programming and live strings. If moves like those, or the speed-blur Bad Brains punk of "!!!!!!!," or the drum'n'bass