Correspondent Vicki Mabrey found the maestro in a small church in Edinburgh, Scotland, giving singing lessons.
"You don't realize how good it is until you've tried it," says Rutter. "It is wonderful to go to a choral concert, to hear a choir sing. But I think the deepest joy of all is to actually sing."
Rutter holds these singing days about 20 times a year. "When I agree to do these, I make just one condition, which is that anybody is welcome," he says. "So long as they are willing to come and bring their voice, they're welcome."
The cost of admission: donation to charity. Singing lessons from the master: priceless.
After a full day of tinkering, fine-tuning and some candid critique, these people – who'd never sung together – sounded amazing.
How does Rutter get the sound that he wants? "Communication through body language or through face language perhaps seems to take over," he says. "There's a kind of alchemy or magic and if I probe into it too deeply maybe I'll lose it."
His requiem was performed recently at Trinity Church in Boston. His works, large and small, are known for their sing-ability. And it begins with just him and his grand piano at this cottage hidden in the English countryside. This is where the extrovert turns inward.
Rutter is first and foremost a composer. He writes a lot of his own lyrics, but also combs books of old poems and sets them to music. He spends hours alone here, playing with sound. But Christmas carols are his trademark. They're especially popular here in America.
What is it about his music that appeals to people, especially in the heartland of America?
"Maybe it touches people's hearts … perhaps that's why it gets so widely done," says Rutter.
He's a prolific writer of carols – that's where he makes a good deal of his money. And his latest was for the choir at Washington's National Cathedral. After just five days of composing, Rutter sent "Rejoice And Be Merry" to Washington, where it debuted last week.
"That's the moment we all live for, because when you sitting composing something, there's the sheet of paper and there's the perfect tape playing in your head of the piece that you're writing," says Rutter.
"But anybody watching you hears nothing. And of course, you write it down and then you pass that along to the performers and when you have that magic moment you just give them the downbeat and baaah!"
Rutter was a musical prodigy, and he was writing at the family piano before he was old enough to go to school. His musical talent gained him entry to Cambridge University, and the choir at Clare College.
Choirs are a tradition at Cambridge, and their haunting chords have echoed across the campus for centuries. Rutter not only sang, he wrote his first works while he was a student. These works caught the attention of his professor, Sir David Willcocks, one of England's most renowned choir directors.
"I think he was the most gifted composer of his generation. And he showed remarkable facility at an early age," says Willcocks, who gave Rutter his big break, and convinced Oxford Press to publish his work.
"They thought, 'Is it right to have such a young man?" So I said, 'Yes, believe me, you'll be proud to be associated with him in years to come.'"
One of Rutter's first hits was "The Shepherd's Pipe Carol," written when he was just 19.
But not everyone loves his music. He's been criticized, especially in England, for being too saccharine – tunes so sweet, as one critic said, that they were all but trail fairy dust.
"Some people say, 'Well that's too much heart-on-sleeve.' Or, 'You know, there's not enough there,'" says Rutter. "What can you say? You can't please everybody. It should be written in gold letters above every composer's bed."
Although he's gained an international reputation, Rutter's career has centered around Clare Chapel and its choir.
For several years after college, he was the choir director. He got married there, and his oldest son, Christopher, was baptized there as well.
Christopher followed in his father's footsteps, and sang in the choir. But in 2001, right after choir practice, Christopher was struck by a car and killed - it happened just outside Clare Chapel. His funeral was held a week later, in Clare Chapel.
"The sadness, of course, never goes. Anyone who's been bereaved knows you never really get over it," says Rutter. "I think anybody who's experienced what our family has knows that it draws you closer together, and perhaps from that closeness comes a sense of inspiration."
For two years, Rutter couldn't find the inspiration. But when he finally emerged, he wrote "Mass Of The Children."
And although he plumbs the bible for many of his lyrics – surprisingly, he says he's not a religious man: "I don't think you have to be religious, or at any rate to seek promote religious faith, to write good religious music."
So does this mean that he's more spiritual than strictly religious?
"Yes, I think that's how I would put it," says Rutter, who has kicked off the holidays rehearsing choirs for a performance of Handel's Messiah at Carnegie Hall. In the next few weeks, during his busy season, he will visit great halls and churches from America to Europe to the Caribbean.
"I love Christmas. It's the child in me," says Rutter. "Maybe I've never quite grown up. I still feel just for those few magic days a year, that we have the world as it might be."
Produced by Michael Bronner and Wayne Nelson