`I think I'm just a tragic case. If a song makes me cry, I want to sing it. The most beautiful songs are written when the head's just been knocked off." The most stunning song on Kate Rusby's superb album, Sleepless, nominated last year for a Mercury Music Prize, is a perfect example - The Unquiet Grave tells a story which can't be bested for sheer tragedy, a love song sung by a young woman to her dead lover:

"Oh don't you see the fire sweetheart

The fire that burns so blue

Where my poor soul tormented is

All for the love of you

And if you weren't my own sweetheart

As I know you well to be

I'd rend you up in pieces small

As leaves upon the tree."

You can't possibly understand this article without hearing her smooth, pure voice, Yorkshire accent intact, doing a swirling dance with her piano around this heartbreakingly lovely tune. Back from the CD shop already? Yes I know it's stunning, didn't I tell you it was? But just as the passion of the young woman's love affair came at the cost of her haunting by her dead lover, so listening to that song comes at the cost of being haunted by it for - well, it hasn't left my head for the guts of a year.

Listening to the lyrics of The Unquiet Grave, it strikes this English Literature major as astonishing that the roots of Emily Bronte's Wuthering Heights were described to us at college as obscure. The story comes, quite obviously, from the folk tradition - Bronte was a Yorkshire woman too. Rusby, who I met at the Celtic Connections Festival in Glasgow earlier in the year, is firmly attached to her native Barnesley, but is not about to wax lyrical about there being a distinctive Yorkshire tradition: "I can't describe it to you - but I feel there is one. I will never leave there. It must be reflected in what I do." She adds an important cautionary note: "I'm not putting myself out as the saviour of English song."

She is a song collector, but an instinctive one: "It's an hour's drive to the next gig and you're chucked out of your B and B at 10 and you can't get into the next one until six - I have my second-hand bookshop ritual. I go into the dustiest corner . . ."

"I were at it yesterday . . . " laughs her father Steve, who with her mother runs the home-based company which produces Kate's work, Pure Records.

She found The Unquiet Grave in Frank Kidso's Songs of Britain. The tunes are harder to find, and even when Kate can find them, she says, with only a GCSE in music, she sometimes can't make them out, so, as in the case of The Unquiet Grave, she composes her own.

Kate Rusby, now 26, has spent her whole life immersed in the folk tradition. Kate's parents are 1960s folkies: they met when her mother formed a singing group and "the other person had a good friend who had a van and it was Steve," as her mother, Ann, explains.

The quiet surge in the popularity of English folk music and Kate's Mercury Prize nomination are explained by Steve with the words, "Oh, folk music's in fashion again. We're on the tail-end of Riverdance and the Celtic boom, from the Bothy Band and the Chieftains. They all saw Titanic . . ."

"But they didn't hear the music," says Kate, who takes a more purist view of the upsurge: "It's because your generation was doing it that we're doing it. There's a generation missing, usually. In England, the 30-somethings are missing."

MUSIC was never forced on her, she says, but she picked up the fiddle at the age of seven and her father taught her three chords on the guitar when she was 15 or 16. "We had an old piano," says Steve, "and it stank rotten. Kate would go into the garage and knock seven bells out of that piano. Her first public appearance was as "Kate and (Barker) Sally sing folk, with Sally singing in G and Kate playing on a D whistle."

She did a spot in a concert with her sister, Emma, playing "foot tambourine" and fiddle. Another promoter saw her, and before long her plans to go to college had been put off for a year. She spent four years as part of an all-female, Scottish-based group, The Poozies and then worked as a duo with Kathryn Roberts.

By then, Steve Rusby had realised that new technology could produce a folk revolution in sound recording: "Kate were already up and running by then and I thought, I'll set up this record company . . ."

The Rusbys have made the local global - "When my sister's child was born, everything got stopped, the door got shut and we all went to the hospital. All the elements of family life are in the middle of the recording," explains Kate. And if she has to take a trip to that hospital herself (her partner is her producer, John McCusker), CD sales will fund her time off. In any case, she gets "homesick" when she tours: "Steve plans Kate's trips the way she wants them," explains her mother. "She doesn't want to be away more than three nights."