Photograph courtesy of Emil Hartvig

Storming from the north like a blast of arctic wind are Selvhenter, the Copenhagen-based group that are set to rearrange your notions of what experimental music can be and do. They will also piss you off. They will piss you off, because you will struggle to find any way to categorise what they do. Taking aural cues from free jazz, heavy metal, noise and even gamelan polyrhythms, the music of Selvhenter is far more powerful than the sum of these parts. Theirs is a sound that is as sonically inviting as it is brutal, as persuasive as it is harsh and makes a mockery of cloistered notions of "art music" through its powerful physicality.

Selvhenter are Maria Bertel (trombone terror), Sonja LaBianca (saxophone splurge), Maria Diekmann (violin screech) and drummers Jaleh Negari and Anja Jacobsen (though Jacobsen is currently out of action on maternity leave). Their democratic, no-holds-barred approach has allowed their music to develop in astounding ways. While their debut full-length, 2012's Frk. B. Fricka is a head-first tumble through raging skronk and angular doom, 2014's Motions Of Large Bodies saw them introduce a greater element of electronic nuance into their sound palette ('Balinesisk Ruder', for example, could pass for a kind of weird techno).

These changes have been cultivated organically under the nurturing force of here Eget Værelse, the collective which functions both as a home to their numerous side projects and as the label on which they release their music. New material from Selvhenter is currently incubating, but nearer on the horizon are Bertel's collaboration with French guitarist Nina Garcia, as well as Negari's solo album Arch Waves, which is due out later this year. Before they play a few dates in the UK this week, culminating in a set at the mighty Raw Power festival, we caught up with the group to understand more about how they're able to create such boundary-smashing music.

Would you be able to tell me a little about when you first started playing music and what sort of things inspired you?

Maria Bertel: We have very diverse musical backgrounds, ranging from classical to rock, jazz and so on. Personally I have always been inspired by dark and noisy music. And that kind of conflicted with my choice of instrument [trombone]. I worked a lot with changing my associations regarding my instrument and ways to play it.

How did you all meet? From my understanding you've been playing together since 2007. When did you become Selvhenter as we know it today?

Sonja LaBianca: We are part of an experimental music scene in Copenhagen, a network of relations, friends and colleges. Some of us had played together previously in different constellations and others met through musician friends. This is how we became aware of each other and recognised a mutual energy driven by the curiosity to adventure into new musical territory. The two horns and violin started things off, exploring the electrification and modulation of our instruments with amplifiers and pedals. We played a few concerts like this and released a mini CD [2007's Lun Elegance], but then came up with the idea of inviting the two drummers. This worked really well and so we took off from there.

What changes have you noticed in the way you interact with each other musically since you started the group?

Jaleh Negari: Through the years we have of course gotten to know each other very well. Each person's musical understanding, tendencies and desires – but also each other as humans, our personalities. I think we have developed our musical language together, so that we can react more intuitively and play along following impulses and ideas more freely. I guess when you get to know each other well and with time develop a big trust and respect in the group, one can more easily let go of the idea of what you think is expected from you. Suddenly ideas and impulses show up that even surprise yourself.

And I see that we get more open to different types of ideas, and more open to different ways of composing. In the beginning we used one way of composing, which now has developed in many different ways, and that gives other results, new sounds and forms.

You've got a trombone and a saxophone – instruments that would normally be categorised as jazz instrumentation. Yet for me your music is almost impossible to pin down aesthetically. Do you see yourselves as working in any tradition at all, musical or artistic?

Maria Diekmann: As we have all been schooled in quite different traditions – jazz, free jazz, classical, folk, rock, experimental and visual art – we have at the same time been listening to all kinds of music and sometimes felt restricted in what we were expected to do with our instruments. I think the concept of noise music was actually quite an eye-opener for us, as it opened up the genres and made it possible to work more in terms of sound and texture. It also helped developing a language that relates [as much] to the visual world as it does to musical terms and genres.

How much of Selvhenter's musical output is improvised? On record things sound very sharp and composed, and equally when I watch videos of you playing live I don't get any sense of you being a 'free improv' group. Could you perhaps explain a little about the importance of both improvisation and composition in your music?

JN: Both composition and improvisation are important aspects of our music-making. For us, improvisation is a good way to meet and sense each other musically and through our instruments. It is a source of many ideas that we wouldn't have thought of via our minds. So the output of improvisation is different than the output of thinking, and we often use improvisation as a tool for making ideas, bits and pieces, which we then compose further on. But it has always been very important for us that the compositions have room for improvisation, that they are flexible and spacious. I guess this also comes from the interest we have for the chaotic, the uncertain and the unexplainable as an element in our music. In that sense, improvisation is one way to include something out of control.

I've seen it mentioned in an earlier interview that you like to approach music-making with certain "rules of energy", that you try a new idea three times and discard it if it doesn't work in that space of time. Is this how you keep things fresh? What other methods do you use to stimulate creativity?

SL: We use many different methods to stimulate creativity. They are constantly changing and evolving as we come up with ideas and collect new sources of inspiration from art, books, films, travel, music and relationships. This is how we keep things fresh. What you are referring to as "rules of energy" I think was at a time when we were fascinated by the Japanese culture of samurai, since we had made our first tour of Japan. We are soon going to visit Japan again for a spring tour in 2017 – hopefully we will take some new inspiration from this!

In Selvhenter, you are clearly very interested in repetitive, danceable rhythms. Was this a reaction against the unrhythmic nature of much of today's free and experimental music?

MB: It isn't a conscious choice to be opposed to abrupt rhythms. I like that energy it brings to music. It has always been important for us in the group not to get stuck on an idea and exclude possibilities other influences may bring. And the choice to go with repetitive songs was a path we took because we like the way it sounds. And also that kind of simplicity, for us, opens up for paying attention to the details in another way.

Are there any leaders in the band or do you approach your music-making democratically?

SL: Yes, we work democratically and always have. This is one thing that we consider a very fundamental element of Selvhenter. Everybody is equally responsible and important to the band and the music. We have learned that the group facilitates a foundation that benefits growth and strength of the individual.

I'd like to talk a little about Eget Værelse, the collective that takes in Selvhenter and all your associated side projects. What influenced your decision to work within this collective? How does it practically influence the way you do things?

MD: We were about to release our first full-length record [Frk. B. Fricka] and talked about releasing it ourselves. At the same time we had all these different projects that we did besides the work we did with Selvhenter. It made sense to create a platform that could present all our projects together, as well as releasing records. It was a way to make our projects support each other.

How much of your time and energy goes into Selvhenter compared to the time and energy you put into your respective solo projects? Do you feel that there is some interaction between Selvhenter's sound and the things you explore in your other projects?

MB: Time, in that sense, I feel is very elastic. The projects we do individually are very much influenced by the way we play in Selvhenter. I would say we get inspired both ways.

Selvhenter play the Exchange in Bristol on May 26, Islington Mill in Salford, 27, and Raw Power festival in London, 28; for full details and tickets for Raw Power, head here