Radiohead's incremental advancement from alt-rock mundane to art-rock majesty was beautiful to behold because the group so carefully calibrated each of its changes. With The Bends, Radiohead paved over the largely inconsequential neo-grunge of Pablo Honey, while its 1997 masterpiece OK Computer rewrote the rules entirely. OK Computer was the rare concept album with a theme revealed only in the abstract, a claustrophobic and sonically progressive tour de force that may or may not have been about man's battle with technology. If that's the case, the highly anticipated Kid A may be about man losing his battle with technology and starting over. Singer Thom Yorke has explained the title as a code for the first human clone, which may explain why so much of Kid A sounds like someone learning to sing in a whole new language. Largely abandoning any elements of rock music, the disc ebbs and flows like Aphex Twin, the hypnotic loops of distorted beats and hissing, humming synths bravely replacing the usual recipe of drums and guitar. The band still makes the music human, but the alien soundscapes are so foreign that it's easy to get lost. Kid A's songs at times contain only wisps of subtle melody, while Yorke's enigmatic lyrics rise out of the murk just long enough to confuse the listener: Rarely have such mumbled blurs packed so much mysterious urgency. The album opens with "Everything In Its Right Place," an eerie hymnal with Yorke's scrambled singing sounding, oddly enough, like everything is in the wrong place. The crystalline title track follows with a wind-chime puzzle box that defies interpretation before "The National Anthem" lets loose with a brassy squall topping sufficiently blunted beats. The transcendent "How To Disappear Completely" (the title of which may as well be Radiohead's business plan) marks the first clear appearance of guitars, though they're transformed into something more graceful (like whale calls) and followed by a mid-album ambient interlude, "Treefingers," that's as foreboding as Brian Eno's best bits. "Optimistic" brushes psychedelic bliss but misses the opportunity for epic status. ("The best you can is good enough," Yorke half apologizes, before teasing, in the hallucinatory "In Limbo," that "you're living in a fantasy.") After the remarkable Warp homage "Idioteque" winds down, "Morning Bell" ends, and the mournful, stunning final track "Motion Picture Soundtrack" fades out, it still sounds like Radiohead has more to say—and it does, with another album or two on the way. Kid A is the sound of a rock band continuing to rewrite the rules so that the old rules (critical, musical, commercial) no longer apply. For all its flaws and intentionally alienating tactics, Kid A—the working title of which was ENC, for "Emperor's New Clothes"—defies expectations and sets the bar ever higher for the would-be copycats, who could learn a thing or two about taking risks. Career suicide? Radiohead is just getting started.