The facts were thin on the ground. Richard D. James was from Cornwall, yes—a geographical outsider in the context of early-1990s UK rave, a kind of coastal cowpoke. He’d been at college for an engineering degree, one he never finished, and was known to pick at the innards of his analog synths. He collected aliases like another young man might sneakers, trotting each one out when the occasion called for it, never letting any of them get too worn: Polygon Window, Caustic Window, Power-Pill, the Dice Man, GAK, Blue Calx, Q-Chastic, AFX, plus his clear favorite, Aphex Twin.

James claimed to sleep just two hours a night; claimed, too, that he could control his dreams, even wrote much of his music in his sleep. He is said to have gotten the jackhammering sounds for “Quoth” from a day job digging tunnels. Did he really drive a decommissioned tank? And as for the bit about being named after his dead brother, you kind of didn’t even want to know. Some people swore he’d cried in interviews, talking about his perished namesake sibling; others were sure it was part of the long con.

Try as you might, you couldn’t quite separate fact from fantasy, or figure out where the truth ended and the fib began. James thrived on ambiguity, possessing a gaslighting nature, David Toop wrote in his 1996 book Ocean of Sound, that “indicates either a serious person who has never been taken seriously or a practical joker who has been taken seriously for way too long.”

I don’t think James ever made anything up maliciously; I think he just liked to talk, to amuse himself, to keep himself from getting bored in the endless parade of interviews a rising star gets subjected to. It’s no wonder an ornery young artist, a prodigy, really, might tell a gullible journalist that, by his 20th birthday, he’d completed 1000 songs, enough to fill 100 albums. No matter how tall the tales grew around this Cornish Paul Bunyan, none of them ever came close to eclipsing the music itself.

James emerged in 1991, at 20 years old, just as UK producers were scrambling to keep up with the newfound domestic demand for electronic dance music. The sound was born in Chicago and Detroit in the mid-1980s and imported to the UK in 1987 when a handful of London DJs stumbled upon acid, the musical style—along with ecstasy, the chemical compound—while on holiday in Ibiza. Their horizons instantly broadened, they connived to bring the stuff back home, and wham: a canary-yellow smiley face landed upon fair Albion like a pallet of rations air-dropped by a benevolent conqueror. Within a few short months, trend-happy (and MDMA-happy) England was consumed with the fever for all things house and techno, but it soon became clear that America simply wasn’t producing enough of the stuff to keep up with British ravers’ ravenous appetites.

Local production went into overdrive, and few native sons or daughters (it was mostly sons) were more determined than James to put their shoulders to the wheel. He’d been making electronic music since he was a young teen, but for years, his output went no further than the cassettes full of demos—not even demos, really, since he had no intention of actually releasing any of it—that he dubbed for friends, who drove around Cornwall unwittingly blasting future classics from their Ford Fiestas.

Finally, though, one of those friends connected James with an Exeter record shop called Mighty Force, which inaugurated its in-house label with James’ debut 12"—Aphex Twin’s Analogue Bubblebath EP—in 1991. The floodgates opened. The following year, he’d release two albums—Aphex Twin’s Selected Ambient Works 85-92, his full-length debut, and Polygon Window’s Surfing on Sine Waves—along with half a dozen EPs that, with their zigzagging rhythms and eerie, metallic timbres, quickly established James as one of UK techno’s foremost innovators.

In addition to techno, ambient music—more than that, really, the idea of ambient music—was in the air in the early 1990s, even if nobody could quite agree on what the term was supposed to mean. Brian Eno had popularized the concept with 1978’s Ambient 1: Music for Airports, positing the idea of a functional sound product, like Muzak but more tasteful, that might be used to “tint” the air. By the late 1980s, it had shifted from Eno’s genre-agnostic ideal to a concept closely aligned with rave culture’s futurist (and hedonist) ethos.

Ambient’s bubble-world atmospheres were well suited to the cybernetic and psychotropic lifestyles then in vogue. As a comedown soundtrack, ambient provided a gentle landing pad for psychonauts returning from the trips of the night before; as a mind-expanding spiritual elixir, it went along with oxygen bars, smart drinks, and other trappings of the dial-up counterculture in the final decade of the 20th century. And, like those AOL free-trial CD-ROMs spilling from mailboxes across the land, it was everywhere.

The KLF’s 1990 album Chill Out and the Orb’s 1991 album The Orb’s Adventures Beyond the Ultraworld gave pre-millennial ambient its amoebic form. Both were long, largely seamless journeys whose ebb and flow mimicked the fluid path of a psychedelic trip—swirling collages conjoining bucolic synths, pedal steel, classical strings, dub and acid-house rhythms, the occasional thunderclap or train whistle, and barnyard animals.

By 1993 the ethereal style was unstoppable. Virgin Records launched a compilation series, A Brief History of Ambient, by declaring it “the summer of ambient” in a full-page magazine ad. The independent label Caroline countered with its own franchise, Excursions in Ambience. The burgeoning style made it into the pages of the New York Times in a 1994 article by Simon Reynolds that noted, “Ambient has become a booming album-based genre, appealing both to burned-out ravers and to people who never really cared for dance music in the first place.” Even Moby got in on the act with his 1993 album Ambient—a collection of sedate yet still rhythm-driven techno that, by today’s standards, doesn’t sound terribly ambient at all.

The same could be said for much of Aphex Twin’s debut album, Selected Ambient Works 85-92. It’s true that, even at its most intense, SAW 85-92 was gentler than his abrasive, reputation-making early singles like “Digeridoo” or “Dodeccaheedron.” But the pumping breakbeats and drum machines of tracks like “Xtal” and “Pulsewidth” were light-years from the interesting if ignorable air fresheners that Eno had originally proposed. Only the beatless “I” suggested anything like the tone-poetic purity of ambient at its most ephemeral. But with 1994’s Selected Ambient Works Volume II, James made a clean break—with his own prior catalog, and with virtually everything else that was being trafficked in the genre.

Then, as now, the first thing you become aware of with Selected Ambient Works Volume II is its purity, its starkness, its emptiness. There have been quieter records, more minimal records, more difficult records. But few have done so much with so little; few have shown less interest in being any more forthcoming than they are, in meeting the listener anywhere near halfway, in making the slightest attempt at articulating their own ambiguous emotional terrain. SAW II can be warm and it can be chilly; it can be sentimental and it can be forbidding, but it would be hard to call it expressive, exactly. A little like those samples of Mars’ terrain thought to contain evidence of amino acids but which turned out to be merely tainted with the sweat of some careless lab tech who didn’t pull his gloves on tight enough, Aphex Twin’s creation frequently seems only accidentally contaminated by human emotion. Whatever you feel when listening to it—well, that’s on you.

The album opens with a subtle tension: soft synth pads, the most basic, three-chord progression imaginable, cycling uneventfully round and round, while a breathy syllable—a voice, or something remarkably like one—bobs overhead, like a loosed balloon rapidly fading from view. Lilting harp accents turn to steel drums and back. The voice is detuned by just a few nearly imperceptible cents; the delay lags almost unnoticeably behind the beat. It’s a child’s lullaby turned queasy, a music box with a whiff of attic mold.

That tension—between disturbing and reassuring, trouble and calm, mutation and stasis—is the album’s defining characteristic. Across its 23 (or 24, 25, or 26, depending upon the format and edition) mostly untitled tracks, the balance tends to tip from one extreme to the other, like someone nervously shifting body weight from foot to foot. Some tracks, like #3 (known by fans as “Rhubarb”) are soft and consonant, welcoming as a well-kept lawn; others, like #4 (“Hankie”), with its bowed metal and whale-song laments, are deeply unsettling. The lilting chimes of #7 (“Curtains”) suggest a fairground populated only by tumbleweeds; the slow-motion grind and whirr of #22 (“Spots”) might be a chopped-and-screwed edit of Lou Reed’s Metal Machine Music. #23 (“Tassels”), recorded on an EMS Synthi, one of the first synths the young artist ever bought, might come closest to James’ description of the album, in an interview with David Toop, as being like “standing in a power station on acid”: “Power stations are wicked. If you just stand in the middle of a really massive one … you get a really weird presence and you’ve got the hum. You just feel electricity around you. That’s totally dream-like for me.”

The four tracks that open CD2 (both the US and UK editions; tracks #13-16 of the digital release) make for a particularly compelling stretch. “Blue Calx”—the only song to bear an official title, it originally appeared on the 1992 compilation The Philosophy of Sound and Machine, credited to Blue Calx—is surprisingly pretty, placid, dreamlike. #14 (“Parallel Stripes”) delicately balances the album’s most tactile tones—I imagine metal shavings dancing across a magnetic field—with a meandering hint of melody. The shuddering, clanging “#15 (“Shiny Metal Rods”) is a tumultuous counterbalance to the album’s gentlest passages, the closest James comes here to the jagged techno of his earlier singles. And #16 (“Grey Stripe”) is pure filtered white noise; it might be the dying breath of a distant star.

Whatever anyone thought they knew about James, back in 1994, must have dissipated as soon as they finished listening to this album. Where was the ginger enfant terrible with the barbed tongue? Where were the antic flights of fancy? These freezer-hum fantasias were the opposite of James’ class-clown personality; they were radically introverted, defiantly private, almost shockingly serene. For once, he appeared as if with a finger to his lips, head cocked, inviting us to stand beside him in his imaginary power station and revel wordlessly in the vibrations.

The title did not help elucidate the album’s mysteries. Much like its predecessor, it borrowed the language of the classical canon—“works” rather than “tracks” or “songs”—and the music’s austerity only heightened the irony. Were these barely-there miniatures, these etudes for electrical outlet and tuning fork, meant to be taken as high art? Although the album title suggested an anthology, these pieces could hardly stand on their own: Pull them apart and most would seem lightweight or insubstantial, each one a passing experiment or sketchlike work in progress. But, like the notes of a chord, they drew meaning from their proximity to one another.

Then there was the matter of that “Selected”: What pool had these two dozen-odd tracks been selected from? Were there indeed more of them? (It seems entirely possible there were: The New York Times reported that the album’s triple-LP, double-CD final form had been “reluctantly cut down from quintuple length”—leaving open the tantalizing possibility that there are at least two more LPs’ worth of SAW II-era material that has yet to see the light of day.)

The album’s secrets were only amplified by its packaging, beginning with a cover that rendered Aphex Twin’s glyph-like logo as a relic from some strange future-past, like alien markings discovered on some weathered desert pyramid. Where the KLF and the Orb’s strains of chill-out had clung to both a stoner’s giggly sense of humor and wide-eyed appraisal of the cosmos, SAW II had no interest in freaky chakras or zen mindstates or any kind of reference whatsoever. It was so committed to its own hermetic world that it shunned even titles. The album’s cryptic cover art, designed by James’ friend Paul Nicholson, referred to each track only by abstract photographs of pure texture, with color-coded pie charts mapping out the tracks’ respective run times. (The titles that fans today frequently use to refer to the album’s untitled tracks grew out of discussions in places like Hyperreal’s IDM listserv. As Marc Weidenbaum details in his 33 1/3 book on the album, those titles were eventually collated by Greg Eden, an IDM list member and eventual Warp Records employee. Though unofficial, they have taken on the weight of historical fact: If you rip the CDs into your computer, the Gracenote database will automatically tag the tracks according to the fan-sourced titles.) Sitting down with the LP or CD insert could feel like strapping into an alien spacecraft and trying to decipher a flight manual written entirely in pictograms and graphic code. “I don’t really like words in music,” James told Select magazine in 1995. “It’s too restricting… I don’t like words in general because they mean something. Whereas electronic stuff—because it’s so abstract and doesn’t have any meaning… you can interpret it in so many ways.”

SAW II was not initially greeted as an epochal event. In The Wire, it was reviewed alongside Future Sound of London’s Lifeforms and a techno compilation called Usability Now, the music barely touched upon, and it failed to make the magazine’s top 50 of 1994. The following year, SPIN favorably compared Aphex Twin’s 1995 record I Care Because You Do to the “largely drumless synth moans” of the “oddly hailed” SAW II, which “went on for longer than the Use Your Illusion albums combined.” Even Simon Reynolds, one of Aphex Twin’s staunchest early supporters, doubted that listeners might extract the same “use value” out of SAW II, in its “dearth of sheer loveliness,” that the more fetching SAW 85-92 provided.

The fan response detailed in Weidenbaum’s book, in online spaces like the Hyperreal IDM list and the WATMM forums, helped buttress the album’s totemic reputation. Like any quasi-religious text, SAW II has proven uniquely susceptible to sustained exegesis. But the album’s essential mysteries extend far beyond any Da Vinci Code-like attempts to decipher them, even as pieces of the puzzle have begun to fall into place.

Two years go, Paul Nicholson, who designed the sleeve, shared the notebooks in which he jotted down all the calculations that went into the album’s pie charts. Those blurry, abstract images were revealed to be objects from the apartment he and James shared at the time—radiators, “bits of metal”—photographed by James’ then-girlfriend; the logo on the cover turned out to have been done by James himself, carving up an old leather suitcase with a razor and compass. And when Warp launched Aphex Twin’s online store in 2017, James—who has turned out to be surprisingly unguarded in recent years—weighed in with a few choice details. “Blue Calx” was the last track he ever recorded in the bedroom studio in his parents’ house; the indistinct voices of #22 turn out to be a murderer’s taped confession, provided to James by a friend who used to mop floors at the local police precinct. In the world of Aphex arcana, those kinds of revelations can be momentous, discourse-shifting events. But the effect of this newfound knowledge was not like learning how a magician does his tricks. None of these factoids has diminished the album’s fundamental and enduring strangeness.

Despite the occasional ambient track over the years, James has never followed up with a Selected Ambient Works Volume III—even though, as Marc Weidenbaum points out, multiple pieces from Aphex Twin’s 2015 SoundCloud dump approximated the metallic drones of SAW II. In fact, immediately after releasing the album, he abruptly shifted course, tacking into the convoluted drill’n’bass rhythms and general tomfoolery of ...I Care Because You Do and the Richard D. James Album. The aspects of James’ character that SAW II had briefly laid bare—beatific calm, transcendent focus, a wordless sort of vulnerability—were quickly papered over with madcap jags like “Milkman” and “Come to Daddy.” For a long spell, in interviews, his answers got shorter while the tales got taller.

For a fan of the album, it’s easy to wish that James might return to its charged air, its field of pure electricity. But it may be that he mapped every square inch of this otherworldly zone in those two-dozen-odd tracks (give or take all the material that may have gotten left on the cutting-room floor). That possibility is part of the album’s power, too: That it’s a world unto itself, self-contained and self-sufficient.

“Music in the future will almost certainly hybridise hybrids to such an extent that the idea of a traceable source will become an anachronism,” wrote David Toop in Ocean of Sound, ambient music’s most definitive text. He was right. In that sense, SAW was out of step with its pre-millennial peers. While other landmark ambient records of the day hurtled toward the networked future, SAW II was radical in its purism, its refusal to admit anything beyond these slim, quivering frequencies. It’s so rudimental that it verges upon the primeval: music for the latent cave dweller in all of us.

We tend to think that culture today moves faster than it used to. We point to the rapid-fire emergence and collapse of a given musical trend as proof of an accelerated timeline. Yet in the early 1990s, culture was moving just as swiftly: “In a year, ambient has degenerated into little more than shoegazing with a beat,” wrote Reynolds in Melody Maker’s review of SAW II. There was a palpable, self-conscious awareness of watching the genre evolve in real time. Criticism recognized it; marketing recognized it. Just think of that Virgin ad proclaiming 1993 “the summer of ambient.” Critics, listeners, and musicians didn’t always agree on what “ambient” or “intelligent techno” or any other nascent term might mean, but they recognized a common goal in trying to figure it out before the music changed shape, wriggled free of any attempt to define it. Wordlessly, instantly, Selected Ambient Works Volume II marked a freeze-frame moment. It captured the essence of ambient, and in that act of capturing it, changed it, irrevocably.