John Rutter: The choir master

John Rutter is the world's most-performed choral composer, and he has a special affection for Christmas. Michael Church watches him working, at his medieval cottage near Cambridge

"If I haven't made a Christmas musical event happen somewhere, it's not really Christmas for me," says John Rutter. "And where better to celebrate it than the Albert Hall?" That's what he's just done, conducting the Royal Philharmonic, plus the Farnham Youth Choir, plus the Gentlemen of St John's, in what he calls his "annual Christmas party" under the hallowed Victorian dome. The programme included gems such as his "Shepherd's Pipe Carol" and Brother Heinrich's Christmas, the musical fable which is his own answer to Prokofiev's Peter and the Wolf.

Shortly before this event, he'd conducted his Mass of the Children at his annual Thanksgiving concert in New York's Carnegie Hall. Before that, he judged the BBC's Chorister of the Year competition: a heartening experience, he says, "as it reassured me about the choral health of the young people of Britain today". Next week he'll plan his forthcoming round of "singing days", which are his way of contributing to that health: choral events in churches and school halls where all-comers are welcome to take part. "And what I most hope is that after it, if people aren't members of a regular choir, they'll join one. Communal activities like this are something we need to rediscover."

Today, the world's most-performed choral composer is at his medieval cottage in the village of Duxford, near Cambridge, editing the recording of a work he wrote two years ago. In 2001, his student son Christopher was knocked down and killed in a road accident, and for the next two years - apart from writing an anthem for the Queen's golden jubilee - he hardly wrote a note. But he'd been invited to write a work for Carnegie Hall, and, in 2003, suddenly decided to add a children's choir to its resident chorus and orchestra, and thus fulfil that commission. "I remembered my formative moment as a pupil at Highgate School, when I sang in Benjamin Britten's War Requiem under the baton of Britten himself. That taught me how enriching it is for a child to perform with professionals, and I wanted to write a piece to bring together children and adults in the same way." Thus did his Mass of the Children emerge.

So was this work, which opens with a Britten-esque vernal sweetness, an elegy for his son? "No, but more than one person has come up to me and said they can sense Christopher written all over it." Did writing it exorcise his grief? "You can never do that. But in some way I did feel happier for having written it. I don't feel I've yet commemorated my son with music in the way that I would like - perhaps I may yet find a way to do that. One of the wonderful things about being a musician is that you can give voice to things which are hard to articulate in words. We shall see."

Composing such music brings a different sort of duty: he replies assiduously to everyone who writes to him. "I would say to any composer who is thinking of writing a requiem: Don't do it, unless you're ready to deal with a lot of bereavement letters. Everybody who listens to any requiem weaves into it their own personal griefs and losses."

Yet most of his music stays resolutely on the sunny side of the street. "A friend of mine one said to me: "Your music wears a smiling face." If you want angst, Shostakovich 10 is always there. I love that sort of thing, but I tend not to write it. Yet Dame Felicity Lott told me she couldn't easily sing 'The Lord Bless You and Keep You' because she kept crying, and she asked if it was written for somebody very special. And I replied that I'd written it for my school music teacher's memorial service, so yes. Now, if a seasoned performer can be moved to tears by an innocent little piece like that, there's something going on that I'm not really in control of.'

Having just turned 60, he's consciously easing up. "It's a milestone, and I don't see why I shouldn't play in the sandpit, and just do things I enjoy. Like most freelances, I work seven days a week, but I no longer want to be on the treadmill the whole time." He's given up commissioned work, though he still responds to interesting challenges. Julian Lloyd Webber keeps asking him for a concerto, as does the young harpist Catrin Finch: both, he insists, will get written, as will a "pageant" work for a cast of thousands to celebrate Liverpool's enthronement as City of Culture 2008.

His daily routine remains unvarying. After dealing with mail and e-mails he drives to his composing cottage in the middle of a field five miles away, where he works until it's time to come home and cook dinner with his wife. Then it's back for the late shift, from 8.30pm till after midnight. "And no alcohol while I'm composing. I love good wine, and I'm picky about my malt Scotch. I know they all make you drunk the same way, but the feeling is different. No, I enjoy the good things of life, but composing is work."

And he simply can't stop doing it. "My wife tells me I'm a workaholic, but that's not how I feel. My life is defined by music, and I'd be heartbroken to be cut off from it, and from the friendships and gossip and encounters it brings. Being a musician is the key to a very happy life."

'The John Rutter Christmas Album' is out on Collegium