The most recent installment of Erstwhile Records’ live series is another, likely the final, document of 2004’s Amplify Festival from Köln and Berlin. And I can say, with no fear of overstatement, that this concert performance takes the music to another level entirely (whether it’s a vertical or lateral move remains to be seen; that is, whether or not this concert represents the apex or culmination of a particular approach, or a shift onto a different kind of musical spectrum). The four players are familiar: Keith Rowe on guitar and electronics, Sachiko M on sine-wave sampler and contact mike, Toshimaru Nakamura on no-input mixing board, and Otomo Yoshihide on guitar and electronics. What’s distinct about their performance is not simply the extremely subtle and rarefied music that is often heard, or even the way in which these four players do things that, even to those most familiar with their work, are surprising; it’s the sheer duration and intensity of the music. At four hours, we are well into Morton Feldman territory in terms of scale, and far beyond the sometimes-rambling approach of another recent long-form exploration in this area, MIMEO’s Serpentine Gallery concert documented on Lifting Concrete Lightly.

After the almost bleak spaces of the Sachiko/Nakamura/Otomo epic Good Morning Good Night, the music on ErstLive 005 can seem at times as dense as an Elliott Carter composition. But that’s only by comparison of course, for one is mostly compelled by the restraint (as ever), the attention to detail, and the patience. Spending time with this music confronts you with your own subjectivity, as active listening is necessary and as it can be fairly forbidding. But these are traits found on multiple recordings, and it’s the sheer scale of this piece—which frustrates and eludes and challenges—that keeps one returning, finding a moment here or a passage there, slivers and particles and granules that make up the whole. The gorgeous packaging, a three-dimensional piece by Rowe, suggests the layering effect that the piece has overall.

The four musicians are responsible—individually and collectively—for some of my favorite improvisational music of the last ten years. But despite my familiarity with their work, I continue to be surprised by the music here. It isn’t simply that each voice is more difficult than usual to pick out—though it’s not quite as easy to identify a Sachiko sine wave or a Rowe gesture as you might expect—and it’s not simply that the music is paced differently. It’s that the music goes to so damn many unexpected places. At times there is a real warmth and intimacy to the music, yet elsewhere it is impossibly remote and bleak. Some moments sound like the most fragile, crystalline noise you can imagine (there is even an occasional tonal gesture which rises up, most likely from Otomo’s guitar); others are almost ruthlessly forceful, as vast bass register chasms loom up. Holding these disparate elements in tension, exploring them at such length and with such focus is what makes EL005 special.

Each disc is broken into four segments, so you can “drop the needle” if you like. The slow accretions of disc one give way to the intensity and glare of disc two, whose opening portions constitute the most densely active period of this improvisation. But disc two also contains—in its second segment—one of this piece’s most sheerly gorgeous sections, a lush reverberant drone (with, I swear, a flicker of some disco song briefly audible). The final disc achieves a real austerity, which some listeners have found serene and others harrowing; certainly it is at this point that the four musicians have blended most completely (or perhaps have collectively effaced themselves most successfully). Initially quite stark seeming, this music over time reveals itself to be quite warm and even intimate, even as it challenges. Numerous small details flicker anew each time though the sumptuous whole hangs together (and it’s this cumulative experience that you’ll remember most).

Anyone interested in this kind of music knows that its balance and restraint are some of its greatest pleasures, as conventional types of expression are sublimated in favor of not simply collective music but music which merges with its environment: it glitters and erupts, advances and retreats, erases then paints. But it is ultimately impossible to narrate, to summarize, even to describe; perhaps those objectives aren’t even desirable any longer. All I can say is that listening to EL005 is a musical experience unlike any I’ve had. A vast landscape of changing substance, richly colored and detailed, this music is practically alive. The best way to appreciate this remarkable achievement is to follow the great Morton Feldman’s words: “Up to one hour you think about form, but after an hour and a half it’s scale.” Give up on finding the whole, on figuring it out, on understanding it. Sit, listen, react, and be amazed.

After such an achievement, which took me months to digest, the two latest regular releases on Erstwhile require an altogether different listening sensibility. Tetuzi Akiyama and Günter Müller’s Points and Slashes is an intense, biting encounter between two pivotal figures in electronic improvisation. The two first played together in 2002 and their recorded work can be heard on a trio track (with Toshi Nakamura) on Erstwhile’s Amplify box from 2003. But the wonderfully caustic pieces on this record are quite memorable. It took me a while to get into this album, and—once I started listening to it on headphones—I was able to hear its subtleties better.

Akiyama sounds as if, in order to best merge with Müller’s incredibly rich sound range, he’s blended the several approaches he’s explored in recent years: the abstractly pastoral, the raucously loud, and the stripped-down metallic flare. He’s credited here with tape-delayed electric guitar, and that’s the secret weapon on this recording. Some tracks (like the first and the fifth) are fulsome and menacing, with guttural noises welling up to lap at the heels of the mean slashes Akiyama gets from his guitar. The contrast between metallic scrapes or whines and the muffled sound akin to rushing air or igniting flame is a rich one. Other pieces explore a different dynamic range, clipped and choked off, pulsing and teeming like an insect hive overrun.

But perhaps the strongest impression is made by the second and third tracks. Track two bubbles and hisses, with the tape-delay quite audible here as neo-psychedelic whispers and choked bridge plucks float ethereally. Initially the music resists coalescing but eventually settles into the sound of an active, ornery hive of hornets being stirred up by Tuvan throat singers. The latter part of this track, the disc’s longest at 16 minutes, has the music dispersing itself at length, as a persistent click-and-hum track drifts alongside Akiyama’s increasingly antic mangled slide asides and percolating delayed fragments. The third piece features more warped tape-delayed guitar here, like the tortured ghost of a Pierre Henry piece or like some sequenza where one person plays while another detunes. Fascinating and warped, this disc is a sleeper.

Misenlian consists of a single, 55-minute track composed through the mail by the NYC-based Dion Workman and Nantes resident Julien Ottavi. These two musicians have produced two of the most captivating solo recordings of the last several years: Workman’s brief, powerful Ching and Ottavi’s vast, at times cataclysmic Nervure Magnetique. Ottavi’s mastery of dynamic extremes can be terrifying, and pairing him with Workman’s slow-burn method is fairly daring. Their duo results in a recording that works by slow accretion. Even when the sound doesn’t necessarily multiply or gather in that sense, it increases in intensity. Its first several minutes explore the contrast between an ominous bottom layer—which pulsates at a varying rate—and upper-end sounds varying from polymorphous hissing to the high whine of something digital confessing its sins.

It’s fascinating, though, how the piece moves and shifts so imperceptibly; every time I listen, it seems I become aware only after the fact that certain musical contrasts—timbral, structural, what have you—have been (at least partially) resolved, though it is probably more accurate to suggest that they have been merged into a new sequence of ideas or events. One third of the way through the piece, for example, while the basic elements of its introductory phase remain audible they are not as present, having been overtaken by cavernous sounds which are more tactile (for lack of a better term) insofar as they seem to suggest some kind of enclosure or encasing (Ottavi can really press the sound down upon you, after all). But it’s all blasted away after a while as the performance reaches a huge, skull-rattling crescendo as a thousand drill bits burn away until a new, grinding space is uncovered in the wreckage. Slowly, over the course of several minutes, a huge full bass drone emerges to a thickening chorus of summer evening insects speaking through digital mouthpieces. Thereafter the piece recedes a bit, like a long molten expanse cooling at last, finally arriving at what Michael Schaumann has suggested is the bucolic sound of water sprinklers. It’s an electrifying document, one of Erstwhile’s finest regular releases from a particularly rich period.