Even when she's singing mainstream country or rock, Patty Loveless retains a high, lonesome sound. "You can take the girl out of the mountain, but you can't take the mountain out of the girl," says the singer from Pikeville, Kentucky, a small town close to the Appalachian mountains.

Her new album, Mountain Soul, is devoted to the old-style music she grew up with. The accompaniments are sparse and acoustic, and it was all recorded and mixed in the space of a few weeks. The music and arrangements are perfect for Loveless. Her voice is remarkably powerful, but also hard and unsentimental - no vibrato, just the occasional slide or ornament.

"As regards my style, somebody said one time that they hear Loretta Lynn, Patsy Cline, Linda Ronstadt and Ralph Stanley."

Perhaps it's Stanley, the bluegrass legend, with whom she has most in common. The album includes old standards such as Man Of Constant Sorrow, Shady Grove (retitled Soul Of Constant Sorrow and Pretty Little Miss) and Two Coats; a Ralph Stanley gospel song, Daniel Prayed; and a duet with Jon Randall on Someone I Used To Know, a song made famous by Dolly Parton and Porter Wagoner. There are also a few modern songs, including Cheap Whiskey by Emory Gordy Jr, Loveless's husband and producer.

Loveless is speaking on the phone from Syracuse, New York, which she is visiting as part of a busy US tour. We're talking early in the day, so she can save her voice for two evening shows. She speaks softly, coughing occasionally and sounding slightly hoarse - it's hard to equate the speaking voice with the singing voice, except for the mild southern twang.

Given its uncommercial style, Loveless has been "pleasantly surprised" by the new album's success. No doubt it has been aided by the unexpected success last year of the soundtrack of O Brother, Where Art Thou? That collection of old-time country, bluegrass and gospel got little or no radio play, yet it has spent the past 38 weeks on the Billboard country chart, where it is still No 1.

But Loveless cannot be accused of jumping on the O Brother bandwagon: she has been incorporating acoustic mountain-music sets in her concerts for about 10 years.

"We bring up the whole band and all gather around one mike. It always got a wonderful audience response." On the record and onstage she aims "to perform as close as possible to the way Lester Flatt and Earl Scruggs did it".

She recalls being taken as a small child by her father to see the bluegrass innovators at a local theatre.

"I was awestruck - not so much star-struck but awestruck." (Scruggs is one of the guest artists on Mountain Soul.)

Growing up in the 1960s, however, she mostly heard music on radio or on records.

"We didn't get a TV until I was six years old. It was a black-and-white, and I always used to think the whole world was black and white except for us. Before that, Momma would listen to the Grand Ole Opry on Friday and Saturday nights on the radio. So on Saturday evening I would sit in the corner of the kitchen and watch her mop the floor while she listened."

When she was 11 years old, the family moved to the city of Louisville, a few hundred miles away. It was a tough time for them. Loveless's father had worked for years as a coal miner, and become seriously ill because of it. They were living off his black-lung and social-security payments.

The move to Louisville was particularly difficult for Loveless. She found herself attending a different school from her brothers and sisters.

"For the most part, I was definitely a country girl," she says.

"Especially at that age, kids don't understand what compassion is . . . And when I opened my mouth I talked different, so it got to the point where I barely talked at all. I was a shy kid anyway, but I became much more withdrawn."

Music offered an escape route.

"By the time I was 12, my dad was able to make payment on a guitar. I took lessons for about a month and I was very impatient. But I continued and my dad ended up buying the guitar. I feel that he saw in some way that I would end up making friends through my guitar - and I did. Also, I started running with an older crowd, so I grew up.

"I just wanted to do what Dolly was doing, what Loretta was doing: I wanted to go out and sing to people.

"Because whenever I would perform, I was nervous before I went out, but once I would get the response from the audience, it was kind of like being accepted. And to know that I was able to move people, to feel that music has that kind of power: it was such a wonderful thing."

Her career advanced rapidly. She auditioned at the age of 14 for Wagoner, who had launched Parton's career. He was particularly taken with a song Loveless had written, The Sounds Of Loneliness, which is the last song on the new album and a remarkable dirge for such a young girl to produce.

Soon she was touring as part of a roadshow with the Wilburn Brothers, a well-known country group. She left home on her 19th birthday and moved to North Carolina with Terry Lovelace, a drummer from the roadshow.

"He and I ended up getting married. We lived together for about five months and I started feeling a little guilty about that. I ended up admitting it to my mother and father, but only many years later."

The next few years didn't work out. She was singing in rock 'n' roll clubs in Carolina, doing anything from Bonnie Raitt to Lynyrd Skynrd and Aerosmith. Then she had an ill-fated stint in the late 1970s, singing with a disco band.

"We were playing hotel nightclubs, and all people wanted was music they could dance to. I was very unhappy. I was getting disconnected from country music and I think my family were very concerned about me."

The marriage broke up soon after, and she returned to singing country. She also changed her name from Lovelace to Loveless, partly because it was easier to pronounce and partly to avoid being associated with the porn star.

She was therefore nearly 30 by the time she released her eponymously titled debut country album, in 1987. She has firmly established herself in country over the past 14 years, but Mountain Soul is the most overt exhibition so far of her musical heritage. "This record enforces my roots: where I come from and why I talk the way I do."

Mountain Soul is on Epic Records