Tool, along with Radiohead, are one of a selct group of artistic visionaries who have the talent and audacity to play by their own rules, and a fanbase rabid enough to follow their journey wherever it takes them. But where Radiohead have taken a complete left-turn from the astonishing song-scapes of OK Computer to the abrasive soundscapes of Kid A and Amnesiac, Tool's Lateralus is more of a sequel to 1996's Aenima - and like all sequels, the results are mixed. Fortunately, no one dies.....

"The Grudge" sets the standard for what is to follow - 78 minutes and 59 seconds of sub-sonic sound exploration, vocal histrionics, big fat riffery and intricate drum patterns of the highest order. And that's partly the problem with Lateralus. Where Aenima chanelled their brilliance into clear and concise musical movements, Lateralus suffers from an abundance of formless meanderings but little in the way of conventional song structures - not that there's anything wrong with that. Indeed, the rumbling bass undertones and sinewy synth sounds of "Reflection" represent the sound of a band at the peak of its powers, especially when underpinned by the sublime percussion skills of Danny Carey (who maintains the impeccably high standard of sticksmanship he set on previuos releases.) Vocalist Maynard Keenan also does nothing to undermine his standing as one of the world's premier vocalists, shifting from barely-audible whispers to high pitched screams at the blink of an eye.

But overall, Lateralus seems to fall just short of its own (admittedly lofty) ambitions. With some more judicious work in the editing room, it could have been their defining moment. In its current form, it is one of those rarest of things - a flawed masterpiece.