Boards Of Canada: the name is mysterious and just a touch forbidding. The group's track titles similarly combine an eye for poetic resonance, nostalgia and the peculiar. Until now the group have remained mute and allowed their music and texts to speak for them, while an ever-inquisitive public have projected their own images upon their shadowy outlines. The lengthy periods of silence that have accreted between their infrequent releases have only served to amplify the fascination.

Music Has The Right To Children (1998) and the EP, In A Beautiful Place In The Countryside (2000), forged their reputation for a haunted nostalgia that at times touched the sublime. Once led into their labyrinth by the dreamy voices of cult members and the laughter of distant children, it's difficult not to find oneself lost in reveries about long-lost polaroids edged with the encroaching darkness of times evermore distant. Boards Of Canada's best work teases the listener with things that lie just beyond reach. The Campfire Headphase returns to the seductive beauty of those works. It also successfully recaptures the fluid coherence fundamental to the success of their hypnotic appeal, something that its predecessor, Geogaddi ultimately failed to do.

Given the foregoing, it seems strange that Mark and Mike Sandison have now embarked upon a concerted campaign of demystification. Lengthy interviews published in The Wire magazine and on the Pitchfork website express their frustration at the public's mythmaking and talk keenly of the ageing techniques that they apply painstakingly to their music. It's difficult to see how such disclosure enhances their art and it's a tribute to the strength of The Campfire Headphase that it survives this puzzlingly banal urge.

As with its predecessors, The Campfire Headphase initially sounds almost too easy on the ear. The music itself offers little more than a tweaking of the duo's template to date. The only real change is the presence of guitars and the reduced prominence of vocal samples (where they do occur they're much more blurred and distant than before). This latter may be a reaction to the relentless puzzle-solving provoked by Geogaddi's multiple references.

Only time will tell whether Boards Of Canada can continue to produce this kind of music without surrendering to the rule of diminishing returns. Despite this concern, the duo remain extremely adept at creating lacunae at the heart of their music, spaces into which you can project your own feelings and memories. As you do so, you'll slip into a gentle whirlpool of slowly emerging sonic details. The effect is seductive and remarkably subtle. A perfect accompaniment to summer evenings as dusk falls, The Campfire Headphase provides a key to the lost art of daydreaming.