At first there is nothing at the end of Björk’s telephone line but a fearsome crackling. Next try reaches the far-distant voice of a female operator, and more dialling attempts yield only a series of high-pitched beeps and squeals. Then between the noises, just as you start to give up hope of hearing another human, there comes a small, unmistakable « Hello ».

« It sometimes feels like feminism didn’t really kick in »

Such a cacophony might be an appropriate fanfare for a musician who has been notorious for her wayward aural inventions for more than a decade, but the more humdrum reason for it is that the telephone company is in the process of changing Björk’s number, having made the error of publishing it in the phone book.

While she spends part of the year in Reykjavik, where her teenage son Sindri lives with his father, Thor Eldon, Björk, now 39, counts as her first home the house across the Hudson from Manhattan which she shares with her partner, the acclaimed multimedia artist Matthew Barney, and their two-year-old daughter, Isadora.

Björk was there when she first saw pictures of the damage inflicted by the Indian Ocean tsunami. « Like the whole world right now, I’m eager to try and do something, and not feeling very capable. » To this end, she has decided to release an album in aid of Unicef – a collection of different versions of her song Army of Me, of which she has been sent dozens, unsolicited, since the song’s release in 1995.

As well as the ’experimental fiddling’ that you’d expect her music to inspire, Army of Me, a trenchant and emotional number, also spawned « death metal and speed metal versions, like really brutal music. Which was a nice surprise », she chimes. Björk first had the idea to compile them into an album when she sifted through past recordings while pregnant with Isadora. Last month, with the impetus of contributing to the aid effort, she encouraged her record company to put out an appeal for more contributions. She is still listening to more than 100 reworkings of the song, and plans to release the album in March.

Aside from this, Björk is pleasurably occupied writing new material ; after the release of last year’s Medulla she decided to break the album-then-tour cycle she has been following since she was a teenager (she released her first solo album at 11 and was in a number of Icelandic bands before launching her second solo career in 1993).

Medulla, an almost entirely a capella album on which she enlisted the rare skills of Inuit throat singer Tanya Tagaq Gillis and human beatbox Rahzel, was recognised by critics and Björk herself as a return to full-lunged, warm-blooded power. She had been laid low after playing the lead in Lars Von Trier’s 2000 film Dancer in the Dark, when she fell foul of the director’s renowned destructive treatment of his female stars. She commented last year : « After filming it, I was at the bottom. Lars has a way of throwing petrol on your soul and burning you. »

Björk gives considerable credit for her regained confidence and productivity to her family set-up. « I feel lucky to be back in a place where I have a working situation », she says. « It’s harder than it sounds, especially for ladies. It seems sometimes like feminism didn’t really kick in. »

With Matthew Barney’s support she has been able to pursue her ’improv, jump-off-a-cliff’ style of working. « You need solitude, and that’s really enjoyable when you haven’t been alone for a long time. » She avoids talking in specific terms about Barney, but ventures that she is writing the soundtrack for his next film, Drawing Restraint 9, to be premiered in June at the 21st-Century Museum of Contemporary Art, Kanazawa.

It is being shot in Japan and New York, and Björk is researching forms of old Japanese music. Although it is the first major project on which she and Barney have collaborated, she has no trace of trepidation. « It is really natural, effortless. The danger is working with people when you don’t really know them », she says. Björk may herself appear in the film. « It’s different to acting, though. His movies don’t have dialogue, for example. It’s more about sculpture. »

Since moving to New York in 2001, Björk has noticed her circle of friends has become dominated by visual artists, but she is emphatic that she would not count herself among their number. « I keep reminding people I’m not a visual artist, I’m such a sonic person it’s silly. I go to see an exhibition and I’ll storm through bored. »

Still, Björk remains almost as eminent for her singular presentation – her fantastical outfits and phenomenal videos – as for her musical output. It was when her 1993 album Debut was released, and Björk was set upon at numerous photoshoots by stylists armed with rails of clothes she would never consider wearing, that she began to take an active interest in fashion.

Björk’s look may have been persistently caricatured as ’bjonkers’, but she has also been recognised as one of fashion’s true radicals, walking the streets in conceptual designs rarely seen beyond the pages of magazines and performing in reality-defying showpieces like the rippling gown made from 30,000 square feet of fabric which Sophia Kokosolaki created for the Olympic Games opening ceremony in Athens last year.

Her Manhattan pals include the collective As Four – four fashion designers who used to share a bed and who showed their debut collection in miniature form on hula dolls, to a soundtrack of Wagner. « I guess I attract people who make clothes the same way that I make music. I’m not that interested in fashion that’s safe, or wants to show off power or status. »

She does only one or two fashion shoots a year these days, wearing new creations by designers including Rei Kawakubo of Comme des Garçons and As Four. In her most recent, with the Italian photographer Paolo Roversi, she stares out of the pictures with a still, sage look. « With me, usually everything has to be new, new, new. He just wanted to make a classic photograph. Some of the pictures look like they could be my great-grandmother. »

Medúlla | interview | Drawing restraint 9 | Army Of Me - Remixes and Covers | styliste | anglais | portrait