Karlheinz Stockhausen might’ve imagined the music of Autechre before Autechre did. The German avant-garde composer and all-around insane genius believed that the emergent off-kilter sounds of his time served a specific function: the full-on enlightenment of the human race. His theory, roughly, was that since the dawn of time, man-made music was largely rooted in the natural rhythms of the body (think a four-on-the-floor house beat echoing a heartbeat) but that advances in technology during the late 20th century gave us the means to create new patterns, and that listening to them would actually help us reprogram our biorhythms in kind. “Such complex rhythms can no longer simply be beaten out, tapped with the feet, danced, or even counted,” Stockhausen explained in 1989. “Exposed to such a process, you quickly establish that human beings change. If such new music is produced, that proclaims the development of a new level of human being.” Eventually, he hoped, these newly rewired human brains and bodies might give us the means to travel throughout space and re-establish our relationship with the higher cosmic beings who created us.

It’s an idea that seems almost tailor-made for Sean Booth and Rob Brown who, together as Autechre, have been making highly confounding experimental electronic music together for the past 30 years. Not necessarily the part about convening with our alien forefathers, but rather the thought that sound and rhythm are learning experiences unto themselves, that our ears can adapt and evolve to new music and bring the rest of our being and consciousness along for the ride. Certainly the past two decades of their career can support this theory. Ever since fully outgrowing the crunchy ambient techno of their earliest work with 1997’s Chiastic Slide, the Mancunian duo has stayed the course, hammering away at a completely singular but ever-growing formula of slithering, glitching, post-hip-hop, post-human music. NTS Sessions 1-4, initially released over the course of April as a series of weekly broadcasts for the online London station NTS Radio, is the latest and longest of these experiments, clocking in at eight hours total, and is likely completely impenetrable to the uninitiated.

This is to say that it’s still very Autechrian. It’s the visceral sound of machines powering down then quickly lurching back into motion. It’s that sense of perpetual rhythmic collapse, the feeling that entire songs are slipping out from under your feet. It’s gorgeous and terrifying and awe-inspiring and incomprehensible and frequently even funky—but only if you let it unfold first. Booth and Brown have so completely mastered their aesthetic that it no longer seems rational to compare it to anything born outside of it. Even when they are proudly flaunting their influences, retracing the daisy chained 808 madness of Mantronix or the nauseating cacophony of early Coil, they claim full ownership. It’s not possible for Autechre to sound like anything except Autechre. And, with each new release, they somehow sound more like Autechre than on the previous one. The sound design is fuller, the programming more intricate, the shock of the new hitting just a bit harder than before.

Their recent output can be easily be seen as a running series of mutations on a single body, particularly since they’ve embraced digital music distribution. 2013’s double CD Exai was two hours long and eventually supplemented by a collection of nine hour-long soundboard recordings of live sets from the same era, all variations on the same setlist but not even close to similar in execution. 2016 saw the release of the Elseq 1-5, a five EP digital-only box set of all new material running at four hours total. And now we have a solid eight hours of new material with NTS. These data dumps are welcome indulgences to their cult following, but they’re also instructional: The more time you spend in this world, the more your body learns to adapt to the rhythms. For years now the duo has preferred to perform to completely blacked-out rooms, forcing the audience to fully devote their attention to the sound itself. A solid eight-hour lump of music is roughly the chronological equivalent to this trick. (The original two-hour NTS airing would repeat on an endless continuous loop throughout the week until the next one aired. This provided its own rather disorienting immersive effect—as the playlist sunk into the background of daily internet use it became quite easy to lose track of exactly how many times you had listened to the same songs.)

Unlike Elseq, which felt more like five discrete projects presented in one long bundle, NTS really does take shape when digested as a single extended piece. Each session runs seamlessly into the next, with an arc that goes from abrasion to bliss, from the 18-minute relentless plod of “t1a1” to the shimmering ambient closer, “all end,” which runs for nearly an hour. In between, the mechanical rhythms bend, bang, and break. More melodic elements—or at least brutal raw chunks of chords, which is kind of their thing now—claw their way out of the muck unexpectedly, and the human emotions creep up on you.

Booth and Brown have always been somewhat cagey about their exact production methods. But their primary tool is Max/MSP, a visual programming language that allows them to create generative algorithms that in effect compose themselves. They’ve talked in the past about the increasing sense that the software is becoming a third member of the group, and the workflow goes something like this: The humans give the computer a set of parameters, then the computer jams endlessly, churning out the requested burps and gurgles, which are passed back to the humans, who edit it all down to a manageable composition. The machine is learning, the composers are learning, and, if all goes as planned, the listeners are learning too.

The more time you spend in this world of sound, the closer you get to understanding its true origin—not the sound collages of Stockhausen’s day, but rather the American hip-hop and dance music that Booth and Brown grew up on. When Booth first heard the scratch-heavy electro of Los Angeles electro party rockers Knights of the Turntables in the mid-’80s it was still incomprehensible to him. “I was hearing it the way I heard Stockhausen,” he told Thump in 2015: “If you look at it purely in terms of the sound and science of it, it’s not that far from musique concrète. But there’s this cultural brick wall between the two things.”

The NTS Sessions, like so much of Autechre’s output, serve as deeply encrypted history lessons through which to tear down those walls. The duo was fortunate to come of age at a unique moment in musical history, that brief period from the late ’70s to early ’90s, when the sonics themselves were stacked higher than that wall. Advancements in production technology were rapidly outpacing their expected purpose and previously inaccessible music-making devices were suddenly attainable to kids from across all cultural and economic lines. Hip-hop and electro, house and techno, bass and freestyle grew out of this cross-pollination and quickly turned weird.

Autechre fully inherited the values of that era and they might be the only artists of our time to still live in them today. So much on NTS Sessions seems to offer a hypothetical alternate timeline to ’80s electronic music: What if it all just kept growing? What if each and every Latin Rascals razor blade micro edit was to re-edit itself violently? What if the stuttering vocals of Miami bass dubs were to develop sub-stutters? If all the acid house squelches grew into roars? If the extended DJ mixes lasted for entire days? And what if all the oh-shit moments that first came with these innovations were still central to the enjoyment of contemporary dance music? It would, presumably, keep evolving until it was no longer even recognizable as such.

In 2013, both members of Autechre held an open Q&A on the fan forum Watmm.com, which eventually grew to more than a hundred pages of conversation. It is an essential text in piecing together the Autechre mythology, not only because it’s their longest and most candid interview to date, but also for how well it illustrates the potential chasms between intent and interpretation. When one user asked, “how would a modern [Autechre] dance track sound?” Booth responded with just one unpunctuated sentence fragment: “but we are making dance music.” The divide between the intellectual and the physical has always been false. It’s all just learning.