Mikhail Baryshnikov, at 48, is still hungry like a shark for new repertoire. Nadine Meisner caught up with his White Oak Dance Project in Spain
It is an odd experience to find the most phenomenal ballet dancer you have ever seen, or probably ever will, rolling at your feet in what resembles a baby's baggy romper suit. Mikhail Baryshnikov is cramming in a few extra minutes of warm-up before a performance in the Spanish port of Santander; and he is trying, with grave courtesy, to answer my questions at the same time. He arches into a backward flop on to the large squashy blue balloon that seems to be the latest dance-apparatus fad, allowing muscles to be both buoyed up and mobile. At 48 he looks extraordinarily good, notwithstanding the past injuries - he has had three knee operations - that tend to mark any dancer's history like battle scars.

He is with the motley crew who make up the White Oak Dance Project, the modern dance company he founded six years ago in the USA with the choreographer Mark Morris, which arrives at the Coliseum for its second London visit. But now, in Santander, the stage has the air of an adventure playground, with the blue balloon, a couple of portable barres, a wooden wedge for stretching legs - and two imperturbable Spanish cleaning-ladies who travel back and forth in parallel, wielding huge brooms. For company class the White Oak dancers normally do ballet exercises; but this is the pre-performance warm-up, for which everyone pursues their own thing, reverting to the habits and preferences of their different backgrounds. Jamie Bishton, formerly with Twyla Tharp's company, is plugged into his Walkman and standing in splay-legged immobility relieved by a few occasional twitches. Patricia Lent (ex-Merce Cunningham) is lying on the floor, limbs spread apart in alarming spidery directions. Baryshnikov, the only one with ballet origins, fuses impeccably turned-out battements en croix with freestyle lurches and stretches.

The Baryshnikov of 20 years ago could halt in mid-air and then turn over on himself like a fish flipping through water; but like all classical princes he was not age-proof. After abandoning that punishing physicality, he could have recycled himself into the sedate mime roles of fathers and wicked fairies en travestie. But White Oak exists because what he has always sought is dance that will bring him new opportunities. And if modern dance is often anatomically kinder (Martha Graham continued into her seventies with leading roles), it also has a creative ferment that makes current efforts from ballet choreographers appear embalmed. As Baryshnikov says: "There is a big vacuum in ballet. Now, if you were seriously good as a ballet choreographer, you would be king of the world."

White Oak marks the culmination of tastes and knowledge Baryshnikov has gradually absorbed in the USA. He emigrated there in 1974 as the last of the big five Russian exiles, starting with Nijinsky and Pavlova, then Nureyev and Natalia Makarova, then Baryshnikov, all from the Kirov Ballet. From 1980 to 1989 he was director of American Ballet Theatre, during which he commissioned and performed work by modern dance heavyweights such as Morris and Tharp. "Although people wanted me to do the old classics, I just wanted to work with choreographers," he says, vigorously rubbing warmth into his right knee. (My God, what are those clicks I hear?) "First, it was ballet choreographers - Robbins, Ashton, Balanchine, Tudor - at that time they were very active." (And now all but one are dead.) "Then it was more modern dance choreographers - Taylor, Cunningham, Graham and later Morris. I learnt a lot from them and they gave me confidence that I can still do something on stage. But it was not a sudden switch. It was a transition over 20 years."

Baryshnikov's stage persona has always suited him to the impersonality of much modern dance. Where Nureyev stormed into history through the blaze of his personality, Baryshnikov soared gloriously over the ballet world with the sublime perfection of his dance. Nureyev was always ultimately Nureyev on stage; but Baryshnikov sank himself into the choreography. He was both the public's megastar and the dancer's dancer. His body was the incredibly fine-tuned instrument of his will and imagination, able to achieve a peerless finesse of movement. The subtle contrasts of texture and dynamic, the turns as smooth as thick cream, the clear-cut geometries: these are qualities he can still unleash today when the choreography demands.

In his crowd-pulling ballet heyday, Baryshnikov was the simple answer to anxious impresarios' prayers. Today, impresarios know they could still sell out - without even having to resort to tiresome marketing legwork - if only they were to write Baryshnikov's name in two-metre high letters on the posters. But, frustratingly, White Oak won't let them. This is not ballet, White Oak replies, this is not the star-system package of ballet; we don't want to mislead. So, in the best modern egalitarian tradition, Baryshnikov is publicised as one of the crowd. Yet if he were injured, they would have to cancel. And if in the group pieces his name is scrupulously listed alphabetically, each programme also usually includes two solo items for him. White Oak both is and isn't a star vehicle.

It is, as one dancer Vernon Scott says, "a democracy with a president". Baryshnikov is open to suggestions, but he makes all the programming and policy decisions. Primus inter pares, he has surrounded himself with dancers of the highest calibre, some with their own successful careers behind them. Cannily, he has selected a satisfying range of ages, from 23 to Rob Besserer's 46, so avoiding the effect either of a Russian sheep among lambs or of a therapy group of dance geriatrics (although the average age is higher than in most companies).

I ask three of the dancers how they joined, and all answer that it was through a sudden phone call from Baryshnikov. "It's like, I'm sitting at home and finishing dinner," remembers Vernon Scott. "I thought it was a joke." How does one qualify for these phoned invitations? "Versatility," says Baryshnikov, "because in our group you always have to alternate styles. We are looking for people who are capable either by experience or by natural ability to change gears." Then he adds: "But that is probably number two requirement. Number one is to fit in the group because we have to travel together." So no homicidal tempers, please.

The dancers need to be adaptable, because White Oak is a rare animal in the culture of modern dance, where companies tend to be one-choreographer outfits. Although White Oak began by devoting itself exclusively to Mark Morris's work, its repertory now covers an enormous span of different choreographers, from modern dance classics like Jose Limn's Chaconne and Merce Cunningham's Septet, to commissions from young creators such as Kraig Patterson from Morris's company. The dancers' diverse sets of experiences encourage a collaborative atmosphere - what someone called trading information.

Linked to this repertorial diversity is an astonishing turnover of pieces, maximum shelf-life being three years. The 1995-6 season has included eight world and two company premieres. Baryshnikov devours pieces like a hungry shark in the search for new challenges, and his latest scheme is to encourage in-house choreography. Vernon Scott is preparing a piece for next season and Ruthlyn Salomons's first attempt will be shown in London. "It keeps the dancers interested and they understand the other side of the coin," are the reasons Baryshnikov gives. Isn't it harsh for the novices - and their audience - to expose them so quickly and uncompromisingly? "You go to a bookstore and there are hundreds of first novels. This is the same. You put those pieces next to the masterworks and it may be hard, but that's life."

White Oak's healthy finances make such prodigality possible. The company enjoys total self-sufficiency, relying on its fees and ploughing back the profits. The only sponsorship has been in kind: the philanthropist Howard Gilman provided a studio on his 8,000-acre White Oak Plantation (and thus also the company's name). The company journeys fast and light - 26 people in all - permitting not only a fair degree of cost-effectiveness, but the freedom that arises from not committing themselves too far in advance to a theatre or a specific programme. Because they see themselves as a chamber ensemble of 10 or 11 dancers and musicians, they aim for theatres with around 1,500 seats, so that at 2,300 the Coliseum is larger than their norm.

The past 12 months have been unprecedentedly hectic, with tours in Canada, the USA, Australia, New Zealand and Europe. White Oak started as an experiment; nobody thought it would last this long. "But here we are in Spain and going on to Israel and London," says Jamie Bishton. "We had a premiere last night and we have other new works on the burner." White Oak will keep going as long as the factors that make it pleasurable continue: no labour unions to deal with, no fund-raising, no early booking commitments. Above all, it gives Baryshnikov absolute control. And who can blame him for wanting that?

White Oak Dance Project performs at the London Coliseum from Tues to Sat. Booking: 0171-632 8300