A child's festive flight of fancy

A song that came to its composer as he walked on a beach in Cornwall gives wings to The Snowman

"The song is fairly engraved in my head, that's for sure," says Howard Blake. He's talking about "Walking in the Air", his signature song for the stage adaptation of Raymond Briggs's beautifully illustrated children's tale The Snowman. In 1985, the song became a Top 10 hit for the choirboy Aled Jones and has been unavoidable around Christmas time ever since.

"It has been used in so many different projects all over the world - animated film, ballet, record, cover song, concert piece," Blake says, evidently still fond of the song, if not a little surprised at its continued success. "I have written as a professional all my life," says the Royal Academy of Music graduate (where he is now a Fellow and visiting professor of composition), "but this is one of the songs of the 20th century, I should think, so inevitably I am attached to it."

"Walking in the Air" had been in Blake's head since the Seventies. "It came to me as I was walking along a beach in Cornwall," says Blake. So when in the Eighties he happened to drop in at TVC, an animation company, and the producer John Coates, who had produced the Beatles' Yellow Submarine, outlined his idea to adapt Brigg's 1978 tale, Blake realised he could use the tune that had been swimming around his head for so long.

It was also "a fantastic opportunity to tell a story with just music," he says. The animated, dialogue-less film, with music composed by Blake, was first transmitted by Channel 4 on Christmas Eve, 1982.

"It was really a time of great synchronicity," adds Blake as he looks back to the early days. "Channel 4 had just opened in Charlotte Street, next door to us at TVC. They wanted us to extend the film from eight minutes to a half-hour television special, and then I got Peter Auty, then lead choirboy at St Paul's Cathedral, singing as the treble soloist." It was a few years later that Jones released his version.

This year marks both the 21st birthday of The Snowman and the sixth year of its successful winter run, at the Peacock Theatre this year.

Nowadays, The Snowman gets about on a motorbike, and there's a disco and and aerial ballet. The production team has devised a new material for the snowman's outfit - made from rouching - that retains the appearance of snow, but doesn't get as hot as the previous suit.

"I had to write another hour of music," says Blake on turning it in to a child-friendly full-length modern ballet. But this year, he won't be conducting his orchestra, which these days consists of five players, rather than 30. Other than a percussionist, flutist and a pianist (with the piano in the orchestra pit), the rest of the music is done by synthesisers - "but it is still faithful to its original score," says Blake.

'The Snowman', Peacock Theatre, London WC2 (020-7863 8222; www.sadlerswells.com)