The eagerly awaited follow up to the 1998 neo classic Music Has The Right To Children arrived wearing a shroud of mystery, sandals of secrecy and enigma earrings.

Without so much as a press release, Geogaddi's addition to the release schedule was enough to whip the music press into a chattering frenzy. Keeping the music and track titles locked away, Warp perpetuated the Chinese whispers until it premiered album number two in six churches; London, New York, Tokyo, Edinburgh, Paris and Berlin. Furthermore, by way of promotion the elusive Marcus Eoin and Michael Sandison conducted just one press interview (for the NME) via email.

Precious little is known about BOC as they tend to work tenaciously in geographical and cultural isolation. Aside from the fact their creative partnership is twenty years old and (having spent some time in Calgary as children) they took their name from The National Film Board of Canada, the world remains conveniently ignorant of biographical details. The onus is on the music, and quite right too.

The Boards of Canada approach is both chaotic and academic. Numbers (six, in particular) feature heavily in their thinking. They belong to an art collective named Turquoise Hexagon Sun and the album measures exactly 66 minutes and 6 seconds (as track 16 freely admits, "The Devil Is In The Details"). Cycling audio through the mechanics of a mathematical equation seems to be as valuable as hours of bashing drums and synthesisers. Who knows, they could be firing boiled sweets out of a nail gun for all we know but the effect is amazing nonetheless.

Geogaddi is a tapestry of strange contrasts. Sweeping synths, crunchy drum patterns and the distorted voices of children weave in and out to create a surreal 'third place'. The ruminant paranoia evident in "Dawn Chorus" is as hypnotic as it is disorienting. Loping beats wrestle with melodies possessed by a blatant disregard for time signature to generate a seasonally affected musicscape. This is electronica put out to graze on the hillsides for fifteen years.

At times BOC invite you to stand with them as they gaze out over the majestic, Scottish highlands surveying an early sunset as it explodes across the horizon. At others they leave you stranded in your flat at 3am wondering whether that strange noise is your speakers on the blink or the mayonnaise growling at you from inside the fridge. Either way, its unlikely you will have heard anything quite like this. Essential.