Adam Cooper really is a one-off. A ballet sex symbol, a gay icon, the world’s most singular Swan, a West End star: Cooper is a true theatrical polymath. The first time I saw him on stage, he was partnering Darcey Bussell; the last time, he was partnering Russell Maliphant. And the time before that he was the Tin Man in The Wizard of Oz. As careers go, it’s been one crazy and unpredictable ride.

Dancer, singer, actor, choreographer, director: they are all on Cooper’s CV. Other dancers have broken away from the ballet mould — just look at Martin Harvey, now starring in Dirty Dancing in the West End. But no one has taken his career to the extremes that Cooper has. At the Royal Ballet he was the edgy but handsome leading man; for Matthew Bourne he was the virile poster boy for a gay Swan Lake. He was Valmont in his own ballet of Liaisons Dangereuses and Sky Masterson in a West End Guys and Dolls. He played the heroes of On Your Toes and Singin’ in the Rain (both of which he choreographed), and the grown-up Billy Elliot in the famous film. So what do you do when you are 37 years old and have all that under your belt? Only the biggest show of your life.

There may be a lot riding on Shall We Dance, the high-profile summer show at Sadler’s Wells, but if the pressure is on, Cooper isn’t letting it show. By the time I track him down to an unprepossessing South London rehearsal studio, the day’s work is done and the other dancers have gone home. Only the musical score languishing on a piano hints at the mammoth task ahead: Shall We Dance, a new ballet by Adam Cooper. “Four weeks to rehearse and stage a full-length ballet with a cast of two dozen — it’s madness,” he says. “I feel as if I’ve aged ten years in the past three weeks.”

He may think so, but to the casual observer Cooper looks every bit as hot as he did when he was prowling the Covent Garden stage in the 1990s, exuding dangerous sex appeal as Tybalt, Rudolf and Onegin. Even his workmanlike jeans and grey shirt can’t detract from his impressive physique or his smouldering masculinity.

Although his 38th birthday is only days away, he shows no signs of pandering to age. “Actually, despite being in my late thirties, I’m all right, Because I left strict classical ballet while relatively young, my body hasn’t come off worse. I feel as I did ten years ago; I’m no more tired, no more stiff. I’ve been kind to my body. Since giving up smoking three years ago I have felt fitter than ever.”

He’ll need to be superfit this summer because he is scheduled to dance every performance during the five and a half weeks of Shall We Dance, a two-act ballet to the music of Richard Rodgers. As well as starring, Cooper is directing and choreographing.

Strangely, Shall We Dance wasn’t Cooper’s idea. Several years ago he approached the impresario Raymond Gubbay with a plan “for an arena show using music by the Prodigy, and instead he came back with a dance show based on Richard Rodgers.” A million miles away from the Prodigy, perhaps, but Rodgers’s Broadway melodies were no less appealing. “What I’ve done is take his music and use it to tell a simple story about a man searching for the perfect woman,” Cooper says. “But he keeps picking the wrong one. He’s a bit like Junior in On Your Toes, a bit naive.”

The hero of Shall We Dance marks a similar change of pace for a man who made his name as a dancer playing beasts and bastards. There was the depraved and sadistic Rudolf in Mayerling, the nasty Tybalt in Romeo and Juliet, and the arrogant, heartless Onegin, all for the Royal Ballet, which Cooper left in 1997 after eight years. There was the mighty feral Swan and the sinister leather-clad Stranger in Bourne’s Swan Lake, a dual role that catapulted Cooper to a mainstream audience in 1995, first in Britain and then abroad. And there was the manipulative love rat Valmont in his own 2005 staging of Liaisons Dangereuses.

Cooper laughs off his old image. “I’m so divorced from playing those roles. When I look in the mirror I see glimpses of how I was all those years ago, but now it’s someone a bit more mature, more knowing and definitely wiser.”

It’s been 12 years since he left Covent Garden but he has no regrets. “I try to imagine what I would be like if I was still there, and I can’t. I lost myself completely when I was at the Royal Ballet, I lost my own personality and I stopped enjoying dancing. Ballet doesn’t offer much for sexy straight guys. Traditionally, it was all about showing off the women, with the men there to make them look gorgeous. You can spend your entire career as a forklift-truck operator moving these ballerinas around. The Royal Ballet is still doing Nutcracker, Sleeping Beauty, Swan Lake. There needs to be a bit more balance between old and new for the dancers’ sake. How about a Matthew Bourne full-length ballet where men could be men? Why couldn’t they do that?”

As an independent artist, Cooper enjoys being in total control. Every aspect of his current production is his responsibility and its success or failure will rest on his shoulders. Four years ago Liaisons Dangereuses wasn’t quite the hit he had hoped, and some day he would like to redress its weaknesses. But for now he has his hands full with Shall We Dance.

This isn’t Cooper’s first encounter with Rodgers. In 2002 he choreographed (and starred in) On Your Toes; and he choreographed the recent West End production of Carousel. Still, it took him three months to go through the Rodgers oeuvre — “There’s so much good music, it’s a case of where do you start?” In the end he decided that listening to Rodgers’s entire output felt like a journey around the world, from the Wild West of Oklahoma! to the Far East of South Pacific and The King and I. So Cooper divided his show into six geographical locations, with a different style of dance in each and, so to speak, a woman in every port.

One such is the actress Emma Samms (probably best known as Fallon in Dynasty), who will be returning to her dancing roots and has been preparing solidly for months to be ready for the show. For dance fans, a special treat is the return of the former ballerina Sarah Wildor, ten months after the birth of her daughter Naomi. Wildor also happens to be Mrs Cooper. “Sarah looks great,” the proud husband says. “She’s back in shape. It’s incredible to see her in a room full of dancers, some of them 15 years younger than her, and she just shines.”

Unlike the hero of Shall We Dance, Cooper isn’t looking for the perfect love. “I have the perfect love, I’ve been very lucky. We have been together for 15 years and married for nine and we are going as strong as ever. We are the right amount of similar and different to make it work. I’m incredibly laid-back and Sarah is not. The most amazing thing is that we are able to work together so well.”

In September Cooper will go to Japan to star in Will Tuckett’s staging of Stravinsky’s A Soldier’s Tale. In November, he appears in a new production of Irving Berlin’s White Christmas at the Lowry in Salford. Cooper will play Phil Davis, Danny Kaye’s part in the classic 1954 film. Cooper may be busy but he knows his limits. “Someone asked me to do the Black Swan pas de deux not that long ago. But I’m not an idiot. I wouldn’t put myself through that ever again. That’s where Rudolf Nureyev went wrong, coming to the Royal Opera House at 50 to partner Sylvie Guillem in Giselle. We all learnt from that. Be clever, do the right stuff.”

Shall We Dance is at Sadler’s Wells, EC1 (0844 4124300), July 23-Aug 30

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