Sinatra swings again

Computer trickery is bringing Ol' Blue Eyes back from the dead. Alice Jones goes behind the scenes during rehearsals at the London Palladium to see how it's done

"Oh, I forgot to ask, how are you with ladders?" says my backstage guide Victoria Hamilton as we trot up endless flights of stairs in the labyrinthine back regions of the London Palladium. We emerge on to the roof of the theatre and look down on bustling lunchtime shoppers. But before there's a chance to take in the view, Hamilton is nimbly shinning down a red iron ladder - the kind you'd only really imagine using in an emergency - attached to the side of the building. I wobble down and land on a small, flat roof that leads inside to the theatre's fly gallery, or, in layman's terms, the balcony at the top of the wings from where the scenery flies out.

This vertigo-inducing trek is all in a day's work for Hamilton, an engineer with Stage Technologies, the company that first brought automation to the crumbling, antiquated theatres of the West End. If you have sat in the stalls and enjoyed the aerial gymnastics of Cirque du Soleil's lithe acrobats, marvelled at the chandelier crashing to the floor in The Phantom of the Opera, or wondered how Mary Poppins is able to hover above your head, holding only an umbrella, you have enjoyed the fruits of Stage Technologies' labour.

Its latest project is Sinatra at the London Palladium, currently previewing before its grand opening on 8 March. This is a musical with a difference, in that its leading man is not really there. Instead of an actor, Sinatra is played by Ol' Blue Eyes himself, resurrected from studio recordings and never-before-seen footage from the Sinatra family archive, projected on to giant screens suspended above the stage. The idea was first unveiled in 2003 at New York's Radio City Music Hall but this is the polished final product, directed by David Leveaux, complete with a 24-piece live orchestra, 20 singers and dancers and choreography by Stephen Mear.

While some may be sceptical about a musical that relies on a digitally reconstructed hero, the army of techies involved are evangelical about the dramatic effects. "You are hearing Frank's voice, virtually the same as if you saw him live," says Keith Robinson, the media coordinator, "but with a better sound system." John Ackerman, in charge of projection, agrees. "I guarantee you that people will come up to us after the show and talk to us as if Frank was there."

This new theatrical experience would seem to be a logical progression for the technology that allowed Natalie Cole to duet with her father, Nat King Cole, on "Unforgettable" 30 years after his death and posthumously paired Sinatra with Celine Dion on "All the Way" in 2001. "It's the visual complement. You're not sitting in a back room, working on it in private," says Ackerman. "Now you're combining it with live performance and showing it to people every night."

Sinatra sold out the Palladium with his first-ever performances in Europe in 1950, and returned to London several times, making his final visit in 1992. Until now that is. "This is the essence of human creativity," says Robinson. "Even guys who are living and standing on a stage, performing, can't lay claim to being as pure as Frank is here."

Among £5m worth of technology, 35mm footage and digitally cleaning up the tracks, Stage Technologies is responsible for moving the virtual Sinatra about the stage on screen. In the past, the scenery and screens would have been moved using ropes controlled by stagehands. With Stage Technologies' system, the winches that move the scenery are operated by a motor which is controlled by a computer. "It's not completely removing the human element. It just means that one person can do a lot more at one time," says Hamilton as we continue our tour of her "office" under the eaves of the Palladium.

The gallery is more homely than expected, with a battered brown-leather sofa, a microwave and a fridge, as well as a television showing Sky Sports (on low volume) and even an exercise bike perched on the rooftop for the odd spot of alfresco keep-fit. Not to mention the bird's-eye view of the stage, where Mear is putting a gaggle of girls dressed in 1940s costumes through their paces, to the mellifluous strains of Sinatra. Shiny new winches whirr away along the wall where the old ropes still hang down. Several white umbrellas, furled and unfurled, hang from the "grid" (or ceiling), ready to descend during "Pennies from Heaven", and a giant aeroplane wing rears up, poised to drop down and become a podium for a dance number.

"They used to bring a front cloth in, everyone scurried around and it's all set up," says Hamilton. "Now it's become a lot more popular to have scene changes in view. It does look more impressive to see something moving without someone pushing it." Stage Technologies was founded on just this principle in 1994, "as a one-man band providing solutions when required". One of its first commissions was Sunset Boulevard and it has since worked on many West End productions, as well as designing systems for the RSC, the Royal Festival Hall and cruise ships.

Hamilton, who has worked at Stage Technologies for eight years since completing an engineering degree at New College, Oxford, has grown used to tempering the whims of theatre directors. Originally, the producers wanted the car in Chitty Chitty Bang Bang to be flown on wires, but Stage Technologies refused, sensibly pointing out that the huge number of wires required would get tangled and that the view of the car's undercarriage from the stalls would be less than inspiring. They settled on the car "flying" on a moving arm, but even this was too much for one actor. "Truly Scrumptious had vertigo. You could see that she was clutching the side of the car with white knuckles, still having to sing," says Hamilton.

They are not afraid to push the boundaries, however. The daring chandelier crash in The Phantom of the Opera was ahead of its time, although, Hamilton reveals, at first it floated rather than plummeted to the ground, and has got considerably faster over the years.

Hamilton has also pioneered the alarming-sounding "3D performer flying", allowing actors to fly up and down, left and right and, as famously seen in The Witches of Eastwick and Mary Poppins, out above the auditorium. Sandbags are used to test the wires first, then it is the turn of the engineers. Hamilton "quite enjoys" this bit. "I've always liked heights."

Does all this insider knowledge spoil the magic of the theatre? "I don't lose any of the enjoyment. Probably I get more out of it. It's more impressive than not thinking about it at all," says Hamilton. Her job, she sums up, is pretty much the opposite of acting. "I guess if we're doing our job properly, people don't really notice."

'Sinatra at the London Palladium' opens on 8 March, booking to 7 October (0870 890 1108)