Disturbed Earth (aka Dean Richards) and Steve Brand are perhaps two of the most visible entities in ambient music at the moment. Brand has been impressively prolific of late, between releases on the Relaxed Machinery label and reissues of his older work via his own Pioneer Light label, and Richards is in high demand for his masterful sound processing and manipulating skills, and also has about 29 releases of his own. Here they combine to craft an hour-long ambient drift that, while quiet for the most part, runs very deep. It’s a headphones-required/lights-out kind of disc packed with sonic imagery. The journey begins in shadow, with serpentine flutes reminiscent of Roach and Obmana’s InnerZone and Spirit Dome twisting off into the gloom. Throughout the disc the flute comes and goes; it may be a guidepost, a sort of sonic silver cord on the way down, or a reminder of the growing distance from the surface of conscious thought. Whichever way you look at it, it works. The duo make an interesting choice, at the end of the flute’s first appearance, to snap the sound off rather than fade it. It’s an abrupt way to mark a shift in tone, but it’s effective. You pay attention. There’s a distinct dynamic at work in this disc as it winds its way through the journey, and it’s often much more subtle than this first change-up. After some dramatic moments following the flute cut-off, What Is Memory? softens slightly while not lightening much in tone. Brand shoots bold pops of chord out of the wash and all the while the pair slowly guide it toward a gentler place–which they reach around the 20-minute mark. From here it’s a stretch of breath-slowing, mind-salving ambient anchored with a rich wash of sound. Wavering tones take over as the voyage continues. The sound grows denser, becoming almost chaotically thick around the 40–50-minute mark, then pares back again. Brand and Richards play with the intensity of the sound in the final 15 minutes or so, creating waveforms that swell, crest, break and reform. Quietly, this superb ambient disc eases itself to a close in a droning wash of sound that turns slightly upward in tone. After a deep breath, you should be ready to take this journey again.

I like that What Is Memory? never quites extracts itself fully from shadow. After all, the recesses of our mind aren’t exactly well-lit places, and to get to the good memories we often have to walk through some pretty murky patches. But the sense of going ever deeper without looking back and wondering if we’ve gone too far–that’s the strength here. The sound compels the journey forward into knowing.

Available from Relaxed Machinery.