GILLIAN Lynne never wanted to choreograph Cats, Andrew Lloyd Webber's now thirty-five year old musical adaptation of T.S. Eliot's poetic suite, Old Possum's Book of Practical Cats. As an internationally renowned choreographer who worked regularly with the Royal Shakespeare Company, and whose career as a dancer had seen her playing Sleeping Beauty at Sadler's Wells thirty years earlier, she was hardly struggling for work. Besides which, she'd just got married to actor Peter Land, a man twenty-seven years her junior, and had other things on her mind.

As a revamped Cats arrives into Glasgow next week for its latest tour following a West End revival, Lynne is glad she said yes to Lloyd Webber, and has remained involved with the show to this day.

“It's like my child,” says Lynne, who is now a somewhat hard-to-credit 90 years old. “It's wonderful. The kids get better every time. They sing better. They dance better, and the show still has the three key elements that make it work.”

Which are?

“Sensuality, sensitivity and sexuality,” Lynne says. “Nowadays life has changed so radically with the advent of the iPhone and everything else, with everyone just looking into screens, that sometimes these things are hard to achieve, but it's a wonderful little company for this production. I've done most of them, and this lot have a very special spark.”

Lynne began dancing aged thirteen, and pursued a long career onstage in the West End and in film, where she appeared opposite Errol Flynn in The Master of Ballantrae. Lynne moved into choreography and directing, working with the Royal Shakespeare Company, English National Opera. Prior to Cats she even worked on seminal TV series, The Muppet Show. Today, however, it is Cats that she is best known for, a show which led her to work with Lloyd Webber again on both The Phantom of the Opera and Aspects of Love. As proved to be the case, resistance to Cats was futile even as Lynne's presence possibly drove the tone of the show.

“Cameron Mackintosh always wanted me to do it from the start,” she remembers of the then young producer, “but Andrew wanted someone else to do it who he thought would be a safe pair of hands. I was rehearsing Oklahoma in Bristol when I got a phone call from my agent, who said I had to go to London straight away to meet Andrew Lloyd Webber. I said, I haven't, you know, because I'd just got married. That's why the show's so sexy, because there's all of our sex in it.”

Somehow Lynne managed to find the time to visit Lloyd Webber at his country house in Newbury

“He played it on the piano all the way through,” says Lynne, “and it turned me on instantly. Trevor Nunn had just done four shows with me at Stratford, so our team fell into place quite naturally.”

For those of a certain age, watching Cats some thirty-five years on, the show's junkyard setting designed by John Napier and role-call of back-alley hipsters can't help but recall 1960s cartoon Top Cat reinvented for stage school kids, with TC's hard-boiled Runyon-esque patois exchanged in favour of T.S. Eliot's equally baroque poetics. Transposed into songs such as the show's breakout number, Memory, such seemingly unlikely material made Cats a sensation. The original production ran in London for twenty-one years for eighteen on Broadway, breaking records along the way.

Back in 1981, however, Cats didn't seem such a safe bet. Following Lloyd Webber's success with lyricist Tim Rice on Joseph and the Amazing Technicolour Dreamcoat, Jesus Christ Superstar and Evita, this was set to be his first full musical since the partnership had broken up. With the Eliot estate decreeing that not a word of the original poems be changed, there was no lyricist at all on board, although there were some lyrical contributions from director Trevor Nunn and Richard Stilgoe.

“It was such a clever idea,” she says. “It was the first sung-through musical without any dialogue, and when we started on it there was no book, no characters, and everyone was against it. John would work on his wonderful set, and we all worked quite separately, so how it became the thing it did was a miracle.”

When Judi Dench, who was set to play ageing feline Grizabella, was forced to pull out of the show through injury, Elaine Paige stepped into her catsuit at the last minute, with the incident adding to the company's collective stress.

“Even at the previews we were s*** scared,” says Lynne. “We didn't have all the money for it, and everyone thought we were raving mad. We were so nervous, and the minute it started we rushed to the bar to have a stiff drink. Then we started hearing this rapturous applause, and we never realised we could do all these things until we had that first reaction, I swear to God.”

Lynne describes what followed Cats' Olivier and Tony winning runs as “a crazy time,” with back to back stints in Vienna, Hamburg and Paris, that continued with runs in Berlin, Madrid, Australia and North Korea.

When the show was revived on the West End in 2014, it wasn't certain whether Cats had used up all of its nine lives or not.

“We didn't know what people would think now,” says Lynne, “or if it would be a success or not, but very pleasantly it was.”

There have been changes for the current version of Cats. One song has been dropped, while Rum Tum Tugger's soliloquy, delivered by Marcquelle Ward with pimp-rolling aplomb, has been re-arranged and transformed into a rap, complete with body-popping gymnastics accompanying him.

It should perhaps be noted here that in the year Cats premiered, Grandmaster Flash and an entire crew of underground DJs had just rapped and scratched their way from underground New York block parties and into the radio friendly mainstream. That it's taken three and a half decades for rap to infiltrate Cats is telling about where Lloyd Webber, Nunn and Co's heads were at – and indeed weren't at – back then. And while no-one onstage will admit it, you get the impression that the addition is not exactly relished by those in the spotlight. Lynne, for one, would have preferred changes elsewhere.

“I was begging Andrew to write a new number for Macavity,” she says flatly, “but he didn't. I've always been open to change, and I really keep my beady eye on it.”

Which brings Lynne, who was made a Dame three years ago, back to what she sees as the driving force behind Cats.

“The sexuality has got to be there,” she says, “just as the sensuality and the sensitivity has to be there, and I think it has all that. I was able to do things onstage with the kids that I wouldn't have been able to do if they were in ordinary clothes. I think people are thrilled to see their bodies move as they do.”

She pauses for effect. “It's without shyness,” she says. “It's dangerous.”

Beyond the danger, Lynne sees something softer there too. “I'm an old romantic,” she says. “I don't think you can have life without romance, but because of the iPhone, I wonder where romance is going to go. So I think it's good that Cats unites people in the way that it does, and I think it might be useful in that way, even though people don't realise it. It's uninhibited in every way, and is so different from life, and yet, it is life.”

Cats returns to Glasgow's King's Theatre, September 13-17 www.atgtickets.com