All hell breaks loose in Leicester Square at 10.30am on Saturday with The Fair on the Square. Entertainment is being laid on thick and fast, climaxing at noon with the start of the '3rd Great Theatreland Bedrace. Under the beady eye of compere Gary Copacabana Wilmot, costumed teams from every show from Phantom of the Opera to The Mousetrap will be racing hospital beds around the square in a series of nail-biting heats (right). In last year's final, Crazy for You musical director Jae Alexander was pushing a bed. 'I've great shoulders from all the conducting, but nothing else. It nearly killed me.'

Jae may not be about to give Arnold Schwarzenegger a run for his money, but he is certainly a powerhouse in the fundraising stakes. 'I'm forever begging people to do things.' There can barely be an Equity member in the West End whom he hasn't persuaded to donate their skill, time and energy to raising money for West End Cares, theatreland's Aids initiative. 'We're part of Crusaid. Their work is so important, particularly the hardship fund which gives out instant payments to those in need. If you're HIV-positive and can no longer dance, how do you pay the bills?'

When not working as a musical director, Jae and his flat-mate Jill Nalder (from Les Miserables) have organised cabarets with the casts of different musicals and also arranged, orchestrated and conducted benefits, and galvanised endless people into raising money. 'We've set up a committee with representatives from nearly every West End show. There's always something going on, from weekly backstage sweepstakes to a sponsored silence from a particularly noisy chorus girl.'

Saturday's brand of gleeful insanity includes Ruthie She Loves Me Henshall unveiling a giant balloon sculpture, the Flying Karamazov Brothers juggling anything they can lay their hands on, Nicholas Parsons hosting Just A Minute live on stage and potential audiences hurtling towards the half-price ticket booth to buy seats for Saturday's matinees at the knock-down price of pounds 5-pounds 10. At 12.45pm, Jae is conducting one of the largest cabarets ever assembled including a finale with over 100 West End performers. Can you afford to miss it?

Fair on the Square, Sat Aug 20, 10.30am, Leicester Square, W1

(Photograph omitted)