Björk is a breaker of boundaries and a creative force to be reckoned with

To describe Björk as a pop star seems a little insubstantial. As Iceland's most famous export, she may tick all the boxes – she's wealthy, wears funny outfits and has had a string of hits – but such a label somehow undermines the artistry and innovation that runs through everything she does.

Björk is a singer, composer, artist, fashion icon and, on occasion, an actor (she won a Best Actress award at Cannes for her role in Lars Von Trier's Dancer In The Dark), and yet she transcends all these terms. She is, above all, a breaker of boundaries and a creative force to be reckoned with. It's no wonder that, earlier this year, she earned a retrospective at MoMA in New York.

That's not to say that she's a po-faced member of the artistic elite. There's a joyousness and humour in her various collaborations. As a teenager she made beats from a tape of her grandfather, fast asleep and snoring. Since her 1993 solo album, Debut, which propelled her to fame, Björk has recorded with Inuit throat singers, Icelandic choirs, sound artists, percussionists and David Attenborough.

Her appearance is similarly constructed with a sidelong wink, whether sporting Nineties mini hair buns, Hussein Chalayan's folding airmail dress or turning up at the Oscars dressed as a swan and laying an egg on the red carpet.

But even with this surface eccentricity, the classically trained Björk brings a high-mindedness to her music. On her newest work, Vulnicura Strings (an acoustic interpretation of her recent LP Vulnicura), she uses a viola organista, a rare instrument invented, but never built, by Leonardo Da Vinci.

In her 30-year career, Björk has rarely stopped questioning, inventing and re-writing the role of the contemporary musician, to electrifying effect. Throughout all this she has remained inscrutable, slightly otherworldly, and always a step ahead of her contemporaries. Her secret is in leaving them, and us, wondering what on earth she will do next.