"I remember the email very vividly. That was when I finished the Mental Union series. And then Grant sent me an email saying, "OK, we've done these tuning system experiments—let's take it to the next level. And then he sent me [the Colundi frequencies], and I just knew that was it. Done making music. Enough of Aleksi Perälä. It's all about Colundi."

It's unusual to meet an artist so keen on denying responsibility for their art. Then again, there's plenty unusual about my interview with Aleksi Perälä. The Colundi he's referring to is the name of a novel tuning system, and a series of releases by Perälä made using that system. It's also, I learn, a spiritual entity. In the past two years, Perälä and his friend Grant Wilson-Claridge, who runs Rephlex Records, have had some kind of epiphany. There's no way to explain such a thing and seem normal, though Perälä does a good job of trying.

"You know that feeling when you hear a really amazing song and your hairs go up on your body? Colundi is that feeling all the time. It's... it's so amazing. So amazing." He hesitates for a long time. "Also very, very difficult to put into words."

I first experienced the Colundi Sequence at Berghain in Berlin. Perälä, performing at CTM festival, played an hour of masterfully subtle techno. Most striking were its melodies: cascades of hyper-delicate sine tones tuned to notes between the usual 12, somehow sweet and sour at the same time. Sometimes the effect recalled the dull glow of Indonesian gamelan, sometimes Jeff Mills circa There's Something In The Sky. Every now and then, a rippling wholetone-like scale would give the whole thing a shiver of wide-eyed wonder.

The gig posed plenty of questions. Perälä, for example, performed next to the sound desk, leaving most of the audience staring at an empty stage. A google search deepened my confusion. Since spring of last year, Perälä has self-released a huge amount of music, starting with a DVD set featuring Levels 1 & 2 and reaching, most recently, Level 14. Most of the releases are album-length, and all of them use exclusively Colundi frequencies.

In spite of this tight focus, the music is diverse, covering twilit ambient, Erik Satie-like keyboard miniatures and reams of hypnotic techno. It's a body of work so huge and engrossing that attempts to map it out are often foiled. Start at any level—they're all available on Perälä's Bandcamp—and before long you're lost in Colundi's uncanny pathways, having forgotten where you started and probably where your day was going. Perälä has 20 years of experience behind him, but this is the best music he's ever made.

When we meet for breakfast in a high-ceilinged Bristol restaurant, Perälä has driven in from rural Wiltshire, where he lives with his young family. The streets outside are chaotic, thanks to the convergence of a university open day and a Refugees Welcome march, but Perälä cuts a calm figure. He's certainly no longer the long-haired kid who, in the late '90s, so neatly fit Rephlex's mischievous image.

Perälä's music back then—first as Ovuca, then as Astrobotnia—followed a trail blazed by Aphex Twin a few years before. He still considers himself and the Rephlex crew to be like-minded. "I've got the same, or similar operating system in my brain," Perälä says. "So we just feel like relatives." A self-described "country bumpkin," he thinks the common ground is upbringing. Just as Wilson-Claridge and Richard D. James reimagined techno in remote Cornwall, Perälä's encounters with the second summer of love, via Finnish radio at the age of 12, were influenced by his rural location.

"That's the whole beauty," he says. "Because you hear only a few tracks that define the genre for you. And you want to hear more but you can't. You can tape some stuff off the radio but not enough. So that's what made me want to start making music. To fill in the gaps."

Perälä discovered Rephlex a few years later while on a student exchange in a tiny town in Michigan, not far from Detroit. "That's when I first heard Aphex Twin, the autumn of '93. And then the next spring, '94, that's when Selected Ambient Works II came out and that changed everything. After that I found out he had his own record label, Rephlex, so I went back to Finland, started sending demo tapes to them."

Perälä's first release on the label appeared in 1999, after four years of sending demos. For a while he adhered to Rephlex's signature style as it slid in and out of fashion, though that's not to say his thoughtful, melodic music was second-rate. An early '00s trio of releases as Astrobotnia offered a particularly lush vision for IDM. But even that project was widely assumed to be a secret alias of Richard D. James. "I didn't mind at all," Perälä says. "It was irrelevant. The music should speak for itself."

By the time of 2007's Project V, Perälä's first album under his birth name, his post-Aphex sound felt rather conservative compared to, say, Rephlex's dubstep-rooted Grime compilations, or the granular mulch of Hecker's Recordings For Rephlex. He was partway through a three-year music technology course in Helsinki, and it was his studies that gave him a fresh approach.

Inspired by mid-20th century minimalist La Monte Young and his Well-Tuned Piano, Perälä began exploring non-standard tuning systems, discarding the 12-tone equal temperament scale used in most Western music. A classically trained pianist, he saw his experiments as a way to interrogate received wisdom.

"It's interesting how it developed over the centuries," Perälä says. "How did it come to this? OK, we have concert tuning, say 'A' is 440hz. But how did we end up with that? It's like we've accidentally developed this thing called music. My beginning of making music was that I played piano for seven years—before I found out about synthesisers and that was the end of playing the piano. I think it's part of that process. You're brainwashed into this at some stage—the 12-note tuning system. And then as you start experimenting with other things you gradually walk away from that. Forget it. Start with a new thing."

"The Moon," from 2009's Boom Blaster, was the first outcome of Perälä's experiments. Its icy techno style prefigures Colundi, though its use of non-standard tunings is subtle. The Mental Union project went further, its four parts sinking progressively deeper into the microtonal depths.

Perälä was keen to share his discoveries, demonstrating on his site how he constructed a series of equal temperament scales, dividing the octave into an increasing number of equally spaced steps. "It all started from 33hz and then built up from that," he explains. "From just one frequency per octave, I went to using two frequencies per octave, then three, four, five all the way up to 32."

Aleksi Perälä:

With the Colundi Sequence, Perälä's research appears to have reached its endpoint. The music is sophisticated and fresh, stripping away the more dated trappings of Braindance. The sound palette is remarkably clear, leaning heavily on sine tones and 909-like percussion. Minimal compression is used, meaning that many tracks don't quite punch enough for dance floor use but make for extremely rich home listening.

As for the maths behind the sequence? Perälä emphasises that it's "not a tuning system; it's a sequence based on specific frequencies, often not related to each other in a traditional musical way." Compared to the rigorous logic of Mental Union, Colundi's origins are far murkier. They lie with Rephlex's Wilson-Claridge, who lives a few hours' drive from Perälä in Cornwall, and seems to be the Colundi project's visionary.

"Grant has arrived at the frequencies, he's done the Colundi Sequence," Perälä says. "128 frequencies. And I don't even know exactly how he's arrived at them, it's irrelevant to me. They were given to him, let's put it that way. But they are not forgetting the history of man and the history of different experiments. You can't deny that certain frequencies just feel better than others. They make you feel good or do good things to you. They help you grow or whatever. Or help you feel the love. They just work and I'm happy with that."

Speaking to the Wire last year, Wilson-Claridge explained that the frequencies were chosen "via experimentation and philosophy, each relating to a specific human bio-resonance, or psychology, traditional mysticism or belief, physics, astronomy, maths, chemistry." He elaborated in a Facebook comment spotted by puzzled WATMM forum members: "E.g. 90-111Hz - Beta Endorphin range. 126.22Hz - 32nd octave of Earth year, The Frequency Of The Sun, Color=Green, Tempo=118.3 BPM, centering of magic, Hara(chakra)."

Perälä says there are plans to publish the full sequence, but not yet. "It's so potent that you have to be careful of it. Because we are right at the beginning of it still. But Colundi will take care of that. It takes care of me talking to you now."

Perälä tests my credulity more and more as the conversation goes on. It seems that somewhere along the line a scientific project became a metaphysical one. At one point, he says that Colundi will come to encompass all world religions. "Colundi's like a huge sphere, and then there's Christianity and Muslims and Atheism and science, little bubbles [underneath it]. I can't put it any better than that."

Later, I mention that we're nearly done with the interview. "No we're not," he says. "I've got lots more to say." I'm a little taken aback. "OK—what would you like to say?"

"I've had the strongest spiritual experience of my life. In June. Friday evening, I was at home doing nothing, sat at the kitchen table, and I started chanting. I'm not into that at all, but I was doing it. Tears pouring out my eyes. Like I was possessed, under a spell or something. Colundi delivered a message. So I scribbled it down. Googled it, it doesn't mean anything, doesn't come up."

He reaches into his backpack and unzips a laptop case, pulling out a few scraps of paper, some of them scrawled with lists of frequencies in different coloured pen. "I feel like a mad scientist," he says. The restaurant has filled up with the Saturday morning crowd, and kids run between the tables. "That's the message," he says, showing me a scrap of magazine on which two indecipherable rows of letters have been written in block capitals. "I couldn't even say it out loud now. Scared is not the word… Yeah. Weird stuff."

The first Colundi releases appeared, in timeworn Rephlex style, with little fanfare or explanation. The strangest thing about them was the format: digital releases were preceded by a limited-run USB stick, cassette, minidisc or magnetic wire recording.

The project's more outlandish side came to light in March this year. Level 9 was launched with a crowdfunding campaign, with the goal of purchasing a "piece of land everybody is invited to share and hold parties at." The Kickstarter page featured an extended text from Wilson-Claridge, in which he described Colundi as "a 'Way of life'" oriented towards "Common purpose, unity, peace & balance."

This caused consternation among fans. On Colundi's lengthy WATMM forum thread, people made comparisons to the Waco siege and expressed skepticism about the legalities of the undertaking. "As far as we all knew so far, Colundi was an album series, suddenly it's a cult-like commune," said one commenter.

"Of course, I don't blame them," Perälä says. "I was really skeptical at first. Grant is my dear, best friend. I love him, I believe in him. But when he introduced Colundi to me and after a while he started saying stuff like, 'This is going to encompass all the religions,' this and that, to me it sounded weird. So I was skeptical until a couple of months later. It all came to me, it's been delivered to me. The effects are very strong, they are very much there."

The Kickstarter was unsuccessful—it fell some $25,000 short of its $30,000 goal—but the pair haven't given up on the idea. "I think it's a brilliant idea. It will come out, the music will come and the place will. There's another place Grant found, a huge plot in Cornwall, near the beach." Another funding drive is underway, primarily through a private Colundi Facebook group. What will they do with the land when they have it? "I think it's just pretty much see what happens. I'm not sure, I haven't had time to think about that, as much as I've wanted to."

As with many of Colundi's wilder aspects, Level 9 was Wilson-Claridge's idea. On the Kickstarter page, he implied that he had closed Rephlex in order to focus on Colundi. He runs the Facebook group for Colundi's "colleagues" and populates a YouTube channel with cryptic films. (Colundi is also listed on LinkedIn as a "think tank.") Perälä also mentions a Colundi costume that Wilson-Claridge has developed, a wearable "transparent blue plastic cone" that might be used as a visual supplement to his live sets.

When I ask Perälä how exactly Wilson-Claridge contributes to the project, his gaze slides upwards and the silence lasts a long time, even by his standards. "I don't know! He's my best friend but I don't know exactly." I flounder around a bit: "He's… just working away on the scale in some way?" "Yeah. As I said, it's really, really difficult to put some things into words."

Perälä claims that he "quit making music" when Wilson-Claridge sent him the scale, and that "Colundi has completely overtaken the whole process." But as the project has progressed, it's begun to seem less like a radical break from the Braindance of old. Not only in Perälä's music, which has sometimes revived old habits (see, for instance, the bouncy final track of Level 14). Wilson-Claridge's years-old definition of Braindance described it, in a remarkably Colundi-like turn of phrase, as "not so much a style of music but a way of life." Perhaps Colundi is just one of dance music's more esoteric cliques doing what they've always done.

In any case, the project has reinvigorated Perälä's music, and with it his career. His recent opening set at Japan's revered Labyrinth festival, as well as the CTM gig I caught last winter, point to the broader recognition Colundi is bringing him.

The project is far from completed. Wilson-Claridge has come up with another set of frequencies, named after the message Perälä scribbled down, which functions as an "extension" of the original sequence. There are plans to cast bells and make instruments according to Colundi principles, and there are a further seven Levels to be completed, assuming Perälä keeps to his initial plan of making 21. He reminds me that he's not in control of the direction things might take. "I'm not doing anything," he laughs. "I don't know, it's impossible to predict what the next level will sound like. I'm very eager to hear it."

I ask Perälä whether he was a religious person before Colundi. "I don't think that's relevant at all. Especially now. I believe in Colundi. As simple as that. I'm enlightened, definitely. After the June experience. After that, when I got the message, for two weeks after that I was constantly all hairs up," he gestures at his forearm. "As if I'd heard something really amazing. Now it's kind of come down a bit, but it's coming back in different waves."

Perälä's epiphany is like any epiphany: utterly real to the person who experienced it, incomprehensible to those who didn't. The difference with Colundi is that it's also produced some extraordinary music.

A few weeks after our meeting, Perälä emails me worrying that there were things he didn't explain very well. He writes a few lines, which begin as bullet-point clarifications and end as poetry:

"Colundi is like a colander, it is the holes;

it is the selected points / nodes.

The stars at night.

Colundi rain."

Like many things related to the Colundi Sequence, you can doubt its sanity, but not its beauty.