BEHIND THE SCENES: The Apollo Victoria's 80th Birthday Celebrations

"We didn't know quite how to mark the occasion," says Adam Caddy from the Apollo Victoria. "So we're having an open day - and then a gala performance."

Though the guest list for the 80th birthday show is celebrity-packed, there'll also be scores of stars on stage, including Christopher Biggins as compere, telling the story of the theatre from its foundation in the 1930s as a cinema to its current status as UK home to the Wicked phenomenon, and taking in its position as concert venue for the likes of Aretha Franklin, Diana Ross and the Rolling Stones.

"The Other Theatres in London are so grand, but they're all very similar," says Caddy. "This is art deco, and we really want to celebrate it."

The cast of Wicked are doing the main bulk of the performing (on top of their usual eight shows a week), with group numbers and a few special solo spots, but there'll be something for everyone. "Because Frankie Valli and the Four Seasons played here, we've got Jersey Boys coming over," says Caddy. "We've got the Divas from Priscilla Queen of the Desert coming across to be The Supremes; we've got Sharon D Clarke, Frances Ruffelle, and the original casts of Bombay Dreams, Saturday Night Fever, Movin' Out - they're all coming back."

James Fox, Topol, Wayne Sleep, Cheryl Baker and Tiffany Graves will also be there - and so is perhaps the theatre's most famous offshoot - Starlight Express. "There are lots of them, coming from all over the world! They've been on their rollerskates on the stage, trying out a few turns, but obviously we have a rake now, which makes it slightly more difficult," says Caddy.

Dedicated Wicked-goers will see a theatre utterly transformed from its usuAl Green-lit self. "It's going to be crazy!" claims Caddy gleefully. Act One will be a tribute to the artists who have played the venue, with Act Two focusing on the musicals who have resided there, ending with Wicked.

Plans for the celebration started back in April, and built to today's large-scale event, complete with a lavish after-show party, allowing for old colleagues to reminisce.

Petra Siniawski, Wicked's UK associate director, is one of the creatives putting the show together, and is overwhelmed by the number of people volunteering their time for free to celebrate the theatre and raise money for the charities, Cancer Research UK and the Entertainment Artists' Benevolent Fund. "What's so wonderful is that people have joined in and been so supportive," she says. "The charities are close to people's hearts and they want to contribute to that."

Check back soon for EXCLUSIVE rehearsal footage from the Apollo Victoria's 80th birthday celebration!

The celebration is on Sunday 10th October, and tickets are available from the theatre now.