Sir John Tavener: Sing, choirs of angels

Sir John Tavener's latest work uses 120 singers and lasts seven hours - but it's fun, he says

"I hope to induce a state of ecstasy, an out-of-body experience," says the composer Sir John Tavener of his latest work, The Veil of the Temple. Commissioned by the Temple Church, London, this massive choral work will last for seven hours, beginning at 10pm and finishing at dawn the next day.

There are those for whom an all-night vigil is more agony than ecstasy, but they can't entirely blame the composer, Tavener says. "I was invited to tea over at the Temple, and remarked that I'd been to an American-Indian ceremonial sun-dance that lasted three days. I said it was a pity that Western music is so inhibited. The Temple took me seriously - and said how about writing something similar?"

It took Tavener more than a year to write the music. "I was saturated in it," he says. "I had no idea what length it would be, but I just didn't stop. It came to about 850 pages and falls into four books." The eight cycles are loosely based on the Christian story, from the Creation to Christ's death, but Tavener has used many different spiritual and religious traditions to enrich his work. "It's a journey towards the centre of the self," says Tavener, "understood by people of all faiths. It contains revelations of God from Islam and Christianity, and then ends on a Hindu note."

The Eastern influence, particularly that of the Orthodox Church, is obvious throughout - as it is in all of Tavener's music (his deeply personal interest in the latter is well-documented). Tibetan temple bells, sounding outside the church, signal the start of the piece. A lone singer, lit by a single candle, summons the listeners inside. A deacon swings incense brought from the holy mountain, Mount Athos. The singing then explodes from all parts of the Church.

"I pray that people don't get stuck in pews," says Tavener. "The nature of it is informal, not like coming to sit stiffly in your seat listening to a Beethoven symphony all night. If you want to go to sleep, bring a sleeping bag. Food is supplied all night. Have a kip. It's more like a rock concert."

Naturally, it's a long night for the 120 singers, who include the choir of the Temple Church, the Holst singers and a small instrumental ensemble. "The conductor has a database of shifts. The choristers will be leaving by 11pm and coming back at 5am in the morning. The brass players have to crawl out of bed very early for the final part. I don't know how they'll feel. It's uncharted territory."

On 4 July, up to 2,000 people will be watching a big-screen relay in Inner Temple Gardens. But, for the less determined listener, there's a shortened two-hour version on 1 July. "My task is to unite different religions of the world so we are united in love. Perhaps music can heal. That was my main intention."

The Veil of the Temple, the Temple Church, Temple, London EC4 (tickets from 020-7638 8891; further info on www.theveilofthetemple.com) full-length premiere 27 Jun; concert highlights and gala dinner 1 Jul; full-length performance & live relay 4 Jul