The curtain has fallen on the matinee performance and two ‘cats’ are perched on a sofa backstage, tucking into microwave meals.

In full make-up and wigs still intact, the cast of Cats are taking a breather before the evening performance.

Since it opened more than 30 years ago, Cats has become one of the world’s best-loved and longest-running shows. Based on TS Eliot’s Old Possum’s Book of Practical Cats, the show is set on the night when the Jellice Cats gather for the Jellicle Ball, presided over by wise old feline Deuteronomy.

Who knew that a musical based on poems about a bunch of cats would become a global smash hit? Andrew Lloyd Webber knew, when he pressed ahead with his vision, despite derision from those who said it wouldn’t last two minutes in the West End.

Cats opened on the West End stage in 1981, directed by Trevor Nunn, and has since been performed in more than 20 countries and about 250 cities, translated into ten languages.

Making my way behind the scenes at the Alhambra, where Cats has arrived for a two-week run, I discover that the on-stage action isn’t the only drama. Backstage, there’s a flurry of activity as the busy crew work hard to get the costumes and set in perfect condition for last night’s performance.

The set, which arrived in a convoy of trucks, is a stunning array of over-sized junk piled up to represent the rubbish tip where the cats gather.

“We can only use theatres that have space for Cats because the set has to stay the same,” says company manager Steve Diamond. “The dancers climb all over it, so everything needs to be in the same place.”

Behind the stage is a dressing-table and mirror, where cast members carry out quick changes. Each performer does their own make-up – they are all taught by make-up artist Maria Cave, who has been with the show for many years – and they stick rigidly to the look of the cat they’re playing.

“The make-up and costumes are very specific to each cat, and the people who follow the show know just what they look like, so it has to be just right,” said Steve.

Further along are racks of furry costumes hanging up, including lazy cat Gumbie’s heavy coat, which looks like something an old lady might wear.

I take a peek at the orchestra area at the back of the stage. With the usual orchestra pit taken up by the junkyard set, which has items spilling out over the stage, the musicians must take their seats behind the set.

Upstairs, wardrobe mistress Trish McAuley is busy sewing beads on to a colourful Siamese cat costume. A cluster of washing machines are whirring in the next room.

“The biggest job between shows is washing the costumes, it’s a very quick turnaround,” said Trish, disappearing into a row of leotards.

With hundreds of costumes on tour, the wardrobe team is kept busy repairing any wear and tear. There are 22 cats in the cast, each one has two understudies and all of them have their own costumes.

Then there are the 28 wigs, which are made from yaks’ hair. “It’s coarse, which is why it’s used for cats’ wigs. It doesn’t droop on stage,” says the production’s wig master, the aptly-named Steve Frizzell. He and two assistants are busy combing wigs on stands, surrounded by hairpins, brushes and huge bottles of shampoo.

“Yaks’ hair is naturally pale grey – we bleach it to white and double-dye it to match the make-up and costume of each cat. Each wig is made by hand and takes 40 hours to create,” says Steve. “There’s a lot of wear and tear on the wigs, the main thing we have to do is de-knot them and clean them every day to get the glue and make-up off. They have to be washed before each performance.”

Wandering through the maze of corridors backstage, I come across various ‘cats’ prowling around. With painted faces, but wearing T-shirts and leggings, they move with feline grace as they go about their business before the call for the pre-show warm-up.

Just time for a saucer of milk, then it’s back to their positions on that rubbish tip.