I ran into Caterina Barbieri after her set at Semibreve, an experimental music festival in northern Portugal. We stood outside the venue as the audience spilled out and started chatting excitedly about the show, with people tapping her on the shoulder to make introductions.

The show had been a success, but all Barbieri could think about was the sound. She had been scheduled to perform in one of the town's many churches, until her music was deemed satanic by the sitting priest. As a last-minute solution, the festival moved her to a monastery, where she played in a long room with low ceilings. Barbieri uses her modular set-up to create dizzying synth arpeggios and patterns. Drenched in reverb, they work best in a space large enough for the sounds to hit and naturally disintegrate.

"Polyphonic music basically was born because of churches," she explained. "Because if you play music in a church you have all these reflections going on, you hear these multi-layered voices and this experience of sound in the space really affects the development of the composition."

A week earlier, we'd met for an interview at Kraftwerk Berlin, the ex-power plant that's home to events like The Long Now and Berlin Atonal. Barbieri likened it to a church. "It has this very harmonic architecture because it's basically three huge connected floors," she said. "You get the huge reverb and reflections and delays that are typical of churches. So the acoustics of the space act as a filter on the music, affecting the perception of the sound but also giving this elevating quality to it."

Kraftwerk Berlin's acoustics had a profound effect on Barbieri's music. She played here in March of 2016, a time when she was using her live shows to work out what would be on her next album, 2017's Patterns Of Consciousness. "That's how my album developed, from performance to performance, and the audience were my victims." Sections of these performances were improvised. "It was crazy, I would never do that now. But that time for me was an experiment. I was interested in hearing isolated sounds in space. [The sounds] get gigantic because it's a huge-scale room. So if you open a filter, close a filter or work with delays it gets really monumental."

As she explained this, a photoshoot took place one level above us in Kraftwerk's cavernous space. Someone dropped something, and we were showered with the falling object's booming reverberation. "In Kraftwerk you can really bring life into the space," Barbieri said. "The room becomes an instrument and sort of a real-life organism because you're stimulating the space with this bright sound."

Acting in the tradition of minimalists like Steve Reich, Barbieri delivers music that's glittering and ascendent, with repeating synth patterns that leave the listener in a trance. "There's a suspension of time somehow," she said, "but there's always motion." Unassisted by a beat, Barbieri's arpeggios are the driving force of this restless energy. The effect, she said, is "a bit like that sort of meditation state that you get when you run or while you're doing a physical activity."

Barbieri's first release, Vertical, and her latest, Born Again In The Voltage, were both recorded around five years ago, while she was studying in Stockholm and had access to a Buchla 200 synthesizer. Her compositions on the Buchla have a more noticeable drone influence, expressed in long, sustained tones with the occasional addition of vocals or acoustic instruments. But as she developed Patterns Of Consciousness on the road with a more limited set-up, she found herself leaning on her ten years of classical guitar training.

"The music I'm doing now is basically guitar music but with synthesizers," she said. Unlike a piano, the classical guitar doesn't have a strong harmonic presence—you can play many different notes at the same time, but the sound decays quickly. Barbieri's set-up makes use of a monophonic oscillator, meaning it can only play one tone at a time.

"I wanted to make something interesting out of just one voice. If you do fast arpeggios, which is typical of the guitar, it's just a way to basically resemble the effect of a harmonic chord. So with my synthesizer I ended up developing this sort of very fast arpeggiated style to resemble the presence of harmony."

Barbieri tends to wax poetic when she talks about her set-up. There's no hiding her passion when she describes her Orthogonal Devices ER-101 sequencer as her "favourite gear ever." Her Verbos Harmonic Oscillator "provides a rich spectrum of sound" she compares to the tambura, a North Indian string instrument.

That said, Barbieri is known to hold the world of modular synths in contempt. "I hate modulars. And you?" reads the caption of an Instagram post of her set-up. Recently, she did an interview for the modular-focused book Patch & Tweak, which she announced on Facebook by saying "I hate modulars but this was a nice interview."

"The modular world is a male world," Barbieri said. "Maybe one of the most male-dominated worlds. And I think it's not a random thing. Guys really like to have this technocratic power, like, 'We know how to play this thing and you will never be able to have this knowledge.'" She mentioned how, after a recent show, people flocked to the stage to take pictures of her rig. "I ask myself, why? Why is there so much interest? Because for me the focus is not on the technology."

This no-frills approach doesn't sit well with everyone in the modular community. "My music is simple and it's maybe somehow pleasant," Barbieri said. "I think some people have a hard time accepting that you can make beautiful music with modulars without having this strong idea of technicality."

Barbieri feels pigeonholed as "the girl playing the modular." "There are so many more interesting things to talk about," she said. For instance: the philosophy behind what she does, how space impacts her sounds, the psychoactive effects of her music. While Barbieri doesn't identify as a sound artist—"I don't even know what a sound artist is"—she does build her music with some conceptual map behind it. She is, after all, an affiliate of Important Records, the label that's championed pioneers of sound art and conceptual music like Pauline Oliveros, Éliane Radigue and Harry Bertoia.

But instead of coming up with a concept and working to execute it, Barbieri channels her ideas and philosophies into her daily creative practice. "For me, art resounds deeply with my life. As I grow up and develop, my music does the same. There's some intellectual part to it, of course, like some theoretical ideas, but it's never only that."

When Barbieri talks about music, its history and philosophies, she speaks in long and detailed sermons. The passion she brings when talking about the architecture of this or the eight harmonic tones of that spills over to her music.

On the right top corner of her black jean jacket is an iron-on patch that reads, in yellow script on purple fabric, "ecstatic computation." It's the name of a piece she premiered at Montreal's MUTEK festival last year, and it's easy to understand the significance of that phrase. Each of her compositions is brimming with euphoria. Every added melody is a chorus of celebration. Barbieri's patterns lead us into a hypnotic realm coloured by bright flares and murky corners. Her music is built in the throes of ecstatic computation.

Caterina Barbieri plays the Resident Advisor event at this year's Re-Textured festival in London.