When it comes to giving interviews, Michael Clark claims to have one overriding golden rule. He won't talk about drugs, breakdowns, alleged self-destructive streak or periods of voluntary exile. What matters these days is the work, the pure essentials of dance. "I think I've just been too unguarded," he says apologetically, in an ante-room of the Greenwich Dance Agency. "It got to the point where all people would talk about were the extraneous details, the costumes, the sets, the props, the life story. So that was when I decided to impose these restrictions."
However, it must be remembered that the very basis of Clark and his work has always been transgression - not so much breaking rules but bringing about their complete destruction. Even as a teenage prodigy in the early 1980s at the Royal Ballet School, he risked everything when he was caught sniffing glue and almost expelled. After graduation, he disappointed adoring tutors by spurning the Royal Ballet and opting instead for the modern dance-oriented Ballet Rambert: "I had no idea what they did. I just knew that they didn't do ballet."
By the age of 20, Clark was a star. But after two years, he turned his back on Rambert and, with his own new Michael Clark Company, ventured even further into the gritty nether regions of popular culture. He created the ballet I Am Curious, Orange with Mark E Smith of the Fall; and in No Fire Escape in Hell, the performance artist Leigh Bowery danced across the stage in platform boots, wielding a chainsaw. Other pieces featured dildos and simulated sex. The works earned Clark, with his trademark shaven head and ear pierced with a nappy pin, instant avant-garde notoriety; even Le Monde praised his "skinhead style".
Predictably, Clark adopted a life-style to match. He acquired a coterie of adoring hangers-on, and during the making of Hail the New Puritan in 1986 he became hooked on heroin, later on methadone. His chemical-fuelled downward spiral coincided with some of his best-known work: a reworking of The Rite of Spring entitled MMM (Michael's Modern Masterpiece), which featured Clark's mother, bare-breasted, re-enacting his birth; and O, based on George Balanchine's 1928 ballet Apollo.
However, after spectacularly dropping out on his first major commission for the Royal Ballet in 1994, he fled to his home town of Kintore, near Aberdeen, where he remained for three years. "I just wanted to be invisible - really get some distance from this thing that I'd created called Michael Clark."
Now 40, Clark appears to have survived his life story miraculously unscathed. He still possesses that luminescent, sylph-like beauty that shone in performances in the 1980s. On the Greenwich rehearsal room floor, as he passes on movements to the company, his slender body moves with the same familiar classical simplicity and grace.
He is working on a piece called Would, Should, Can, Did, a series of seven new "experiments", that premieres at the Barbican this week. At first, it's difficult to make out what is going on as the dancers flutter and pirouette to four related but apparently entirely distinct pieces by the composer Erik Satie. Everything becomes clear when they join up for the climax, the music sometimes violently clashing, then coming together in electrifying harmony.
"I've been trying to do something to Satie's music for a long time," says Clark. "The pieces are called Four Ogives, a term that refers to details from Gothic architecture. Each is a very different variation on a central musical idea, played softly and then strongly. So they are perfect for a dance like this. I like to think that it is something Satie himself would have approved of."
The brainwave of bringing it all together came, inevitably, from popular culture - specifically, the work of DJ Richard X. "What he does is puts two records together, usually quite a contrasting choice: the Human League and Chaka Khan, or Gary Numan and the American singer Adina Howard. So this is not really an innovation."
Clark undeniably has a talent for combining arresting styles - but is his work actually contributing anything new to the lexicon of modern dance? The basic technique underpinning all his work is almost sacrilegiously conventional. "My teacher at the Royal Ballet School has always said that all my work is a continuation of his training," Clark admits. "I think there might be some truth in that."
Asked whether his work is neo-classical or postmodern, Clark says: "I'm certainly not a one-big-idea type of person." So do his ideas come from his tortured life story, the drugs, the breakdown? "I won't deny that it informs the work. But I don't recognise words like breakdown and depression and addiction."
Clark senses that he is about to break his golden rule, but continues with characteristic abandon: "I guess there were different phases to it all. There was certainly a phase of: yes, I have started this, there isn't really a lot I can do about it but just carry on. Methadone was the really the biggest problem, but it was kind of manageable because I could continue working. I wasn't one of those docile, placid, agreeable addicts. I was very driven, and not in an attractive way. For the rehearsals of MMM, the obsessive side of my nature was given full range."
Finally, the combination of addiction and dedication to work pushed him over the precipice. "I had this huge crisis where the gap between what I was trying to do and what I was actually doing seemed impossible to bridge. At one point I was convinced that the messages couldn't get from my brain to my body."
And so he retreated to Kintore, where he claims to have spent the first year in his bedroom, drying out. "I think that probably one reason that I got through it was that I knew there was this thing that I could do that gives me a great deal of satisfaction, and fortunately other people like it too. It defines who I am." At this point, Clark becomes rather sheepish. "I always say that I'm not going to talk about this - and then I always do."
It's difficult to banish the suspicion that this is something of an act, and that Clark himself is aware how much his work has relied on peripheral details. Without the dildos, chainsaws and rock ambience, he might have passed into British dance history as the purveyor of interesting, balletic but ultimately rather conventional pieces. Certainly, the mythology of Michael Clark would not be so potent were it not for the dangerous edge of addiction and self-destruction.
When he emerged from Kintore in 1988 with Current/SEE, critics complained (and some rejoiced) that it was too "pure" and free of gimmickry. Would, Should, Can, Did may be a sign that Michael Clark is entering a more mature stage: that the shock he once achieved with props is now generated by a crisp, arcing, sublime idea. "If I look back to 1988 and think of the excess and abundance of everything, I find it kind of obscene," he says. "It's good now that I don't have people to indulge me. So the way that my behaviour has changed is quite a leap. It's taken me a long time to believe that dance itself is enough."