With Geogaddi, Boards of Canada have pulled off another album worth of intriguing Asperger's pop. They haven't screwed with the formula too much, the same mix of reductive hip-hop rhythms overlaid with ghostly pads and textures, with the odd daft voiceover from old instructional films. So no great revolution there, though when you consider that Music Has The Right To Children was one of the great dance-related albums of the 90s, that's not such a bad thing.

Having said that, Geogaddi subtly ups the ante in the catfreaking department whilst sounding more together, and that makes all the difference. The ideas are more coalesced into set pieces, "1969" possibly being their most structured song yet. And yet it's still not all that blatantly accessible.

The title of the first key track sets the tone, "Music Is Math" which is taken almost as an article of faith, extrapolating from previous album's "Aquarius" which had that goofy trick of counting up numbers to 36 and then going haywire. "Gyroscope" features hurtling breaks over seems to be the recording of some dorky kid counting off numbers whilst being spun around a playground merry-go-round at some rate, presumably he'll get fly off the thing and bang his head on a nearby treated pine beam and get minor concussion. "Alpha and Omega" is scariest of all, sounding a little like one is being assimulated as they are consumed by hyperintelligent insects from another planet.

There are the barest echoes of other outfits: "Dandelion" with its grab from a doco about volcanos reminds me a little of Air's "The Word 'Hurricane'" from their Virgin Suicides soundtrack. "The Beach At Redpoint" sounds vaguely like something off Orbus Terrarum. But these rare intrusions from the outside world barely impact apon the overall BoC noosphere. If nothing else, their knack of evoking half-forgotten memories of one's childhood is a good one, and for whatever unpleasantness that may involve, the Geogaddi experience is still pretty marvellous.