A very pretty 57-year-old, by the way. Tricked out in a scarlet sloppy Joe and black velvet hat, she doesn't exactly look young for her age, but there is an air of youth about her. Notwithstanding her edgy reserve, today is a relatively relaxed day - one of the three days each week when she isn't dancing the nymphomaniac Queen Mother in the West End run of Matthew Bourne's hilarious yet heart-breaking re-think of Swan Lake.
Seymour first saw the show during its premiere run at Sadler's Wells last year - "I went twice, because I loved it so much". So she was already a fan when the original Queen Mother, ex-Royal ballerina Fiona Chadwick, pulled out of the West End run (to concentrate upon her new job at the White Lodge Ballet School), and Bourne offered Seymour the part instead. Her guest season has given a huge fillip to her own career and a boost to the box-office. Her starry presence has also changed the way people view the production. Turning the spotlight on to Siegfried and swapping the tutu'd chorus of swans for a skein of powerful male ones has a huge dramatic impact, but its shift of emphasis has led to the show being seen as a "boy's own" ballet. Seymour's high-profile guest-spot reminds everyone that this is far from being the case.
"There's a lot of this `all-male ballet' stuff, yet there's a whole bunch of fabulous females creating marvellous roles and dancing their feet off." Seymour is now one of them, and dancing four nights a week has left her in excellent shape. Today's Royal Ballet dancers may be lucky to get one or two goes at a role each season, but Seymour began her career in the barnstorming Royal Ballet touring troupe, so Swan Lake's long run poses no problems for her: "It feels like home. It's the way I started out. I used to do three Odettes a week. Of course it's taxing, but you pare it down to all it needs. You take away all the excess."
She learnt to maximise her resources by watching some of British ballet's greatest stars: "Svetlana [Beriosova] and Margot [Fonteyn] helped me in Swan Lake, Fred [Ashton] coached me in Sleeping Beauty, Robert Helpmann helped me a lot with Giselle. I was really lucky. And Rudolf... Rudolf [Nureyev] was very generous. He was so interested. We were luxuriating in trying things out and we'd work extra hours to get something right. At present, I think of Fonteyn daily, because I used to watch her in class, how she looked after herself. I've got a role-model there."
Seymour herself provides a role-model for today's Royal Ballet principals, coaching them in Kenneth MacMillan's harrowing dance-dramas like Anastasia and The Invitation. It can be frustrating as well as stimulating: "They would all benefit from more time. Rehearsals are so short; they have so few performances. I feel terribly sorry for them. We were very fortunate when we were creating - we were led to think the roles would be ours." She does as much as she can to convey to her young pupils something of the passion that marked her own performances: "There was a run in Anastasia that nobody was doing properly. So I made them scream as they ran. It seemed to help."
One thing she can't provide for them is the perfect partner. Seymour's heyday was famous for dancers who pair-bonded as closely as doves: Fonteyn and Nureyev, Sibley and Dowell, Maximova and Vasiliev. Today's ballet dancers are more promiscuous, taking partners as they can find them. Seymour regrets this: "It's so divine when you find the right person. If your chemistry is right, there's nothing like it." In the event, she danced with Nureyev, Baryshnikov, David Wall and Christopher Gable, but never really went steady with anyone. "Christopher would have been the one, but he left dancing for acting. I adored working with Rudolf, but I couldn't have him."
Seymour was recently re-united with her first Royal Ballet partner, Donald MacLeary, in a forthcoming "Dance for the Camera" film for BBC2. "It's about two people who were innocent lovers in childhood, meeting up again 30 years later. But it's not a sentimental romance at all; it's troubled waters."
Because she had prepared so thoroughly for this film, she was already back in shape when the call came for Swan Lake. It had been three years since her last performance: did she still suffer from stage fright? "Oh, sure. But with this at least I knew I had time to redeem myself if I made a horrible mess." As if. While she may not have created the role, she has already made it her own, bringing out the pain and pathos in the character of Siegfried's emotionally crippled mother. "At first, I had thought to play her much more nastily; but, after a chat with Matthew, I decided it would be too obvious to just show her horrid side. She's more complicated than that."
With only minutes of the interview to go, she finally warms up and speculates hungrily on Bourne's next project, Cinderella. Will he ask her to be in it? "I hope he won't hesitate now that he knows I'm gung-ho for the company." Her mouth waters at the thought of getting her teeth into the part of the wicked stepmother Baroness Hardup: "The performance isn't the whole thing - it's getting there that's interesting. I remember one of the times I gave up ballet, it was such a great relief. I didn't miss performing; what I missed was being in a creative atmosphere"
Lynn Seymour dances in `Swan Lake' tonight, Wed, Fri and dates into January. Piccadilly Theatre, London W1 (booking: 0171-369 1734)