One often thinks of Niblock's music in terms of slabs. Thick, rich, marbled slabs of sound that vary over their course only marginally but carry massive weight and ooze with sonic calories.

At the beginning of "Stosspeng", a work written for Susan Stenger and Robert Poss on electric guitar and bass, you can even hear what sounds like floorboards creaking under the sheer massiveness of the work. It's essentially an hour-long drone but within that drone, there are throbs (low and lower), apertures where high keens emerge and disappear, wavering lines that coalesce into momentary patterns before fragmenting back into a less differentiated matrix and much more. It's a testament to Niblock's ability to make just the right choices in pitch, resultant interference patterns and volume that he's more than able to sustain interest over the length of the work. Played loud, as it should be, one's speakers rattle but the listener is immersed into this murky yet luxuriant world, objects appearing and receding in irregular sequences, the deep hum becoming all-enveloping.

"Poure" was written for cellist Arne Deforce and consists of the A and D notes played in several octaves, layered atop one another in the final work. Oddly, the pitches chosen connote, of all things, bagpipes! You feel as though caught in a room aswirl with several ensembles of strings and pipes, all tuning to one of these two notes. It gradually builds in intensity (and density), acquiring dervish aspects, vibrating on the edge of explosion. A powerful piece — when it ends, the silence is stunning. The final piece on this 2-disc set is "One Large Rose", performed by the Nelly Boyd Ensemble (Robert Engelbrecht, cello; Jan Fedderson, piano strummed with nylon strings; Peter Imig, violin; Jens Roehm, bass guitar strummed with nylon strings or e-bow) and more or less picks up where "Poure: left off, save that the drone has greater breadth. It's somehow more serene, less overwhelming that the previous two works, causing one to listen differently, perhaps to appreciate the subtleties more, a 46-minute debriefing, as it were.

Two hours of serious, concentrated listening. Recommended.