Boris With Michio Kurihara - 'Rainbow' (Drag City) Released 21/05/07

Last time we heard from Boris, they unleashed the monumental 'Altar', a pulverising platter devised in collaboration with robe-sporting US doom-drone overlords Sunn0))). If you're expecting more speaker-shredding slo-mo symphonies from the follow-up, a not unreasonable assumption considering that the three-piece has teamed up with Ghost guitar whizz Michio Kurihara, famed for a noise-intensive six-string style dripping with skyscraping drama, the subtle and subdued sounds of 'Rainbow' may come as a shock-scale surprise.

Mountain-levelling opener 'Rafflesia' and the Stooges-ian scuzz-blues feast 'Starship Narrator' aside, 'Rainbow' skirts Boris's trademark gloomy sludgefests, metallic textures and eardrum-battering blasts of feedback-fuelled racket almost entirely. Instead, the Japanese noisenik trio and their improv champ special guest follow the lead of 'Altar's least representative and most stunning track' - the foggy Jesse Sykes-helmed swamp-dirge lament 'Sinking Belle' - by embarking on an expedition to chart their rarely visited melody and nuance departments. Such risk-taking departures from a band's comfort zone can easily result in an awkward mess, but Boris and Kurihara land with a jaw-dropping jackpot by leaving enchanting wide open spaces where you'd normally find throbbing slabs of dense riff-sprouting heaviness.

Yet this is far from a tame easy-listening lounge meeting. An immensely rewarding, endlessly diverse yet unified heady brew, 'Rainbow' draws equally from the freakier regions of classic rock, metronomic krautrock grooves, hazy-eyed psychedelia, screeching six-string pyrotechnics, even weightless post-rock atmospherics (the needlessly brief ambient beauty 'My Rain'), with Atsuo's astoundingly agile drumming deservedly in the foreground.  Of the highlights, the hushed title track packs more than a whiff of Can's minimalist funk, whilst the high-pitched guitar wail fermenting the steady-rolling 'You Laughed Like A Water Mark' resembles Neil Young hacking splinters off his ax and the astounding 'Fuzzy Reactor' could be John Cale-era Velvet Underground slugging it out with Neu! Even better, the desolate 'Shine' proves the validity of Boris' policy to allow notes room to breathe by escalating from near-mute delicacy into a devastatingly majestic anthem for some scorched post-apocalypse landscape, whilst the Comets on Fire esque 'Sweet No. 1' offers Kurihara a chance to let rip with screeching, chaos-embracing gusto, being at the receiving end of which offers a fearsome glimpse of what exposure to the flaming belches of a ticked-off dragon must feel like.

An essential addition to the ever-growing canon of neo-psych brilliance, 'Rainbow' provides welcome proof that amp-busting excess and decibel overloads aren't the only available routes to earth-trembling intensity.