With little promotion, Scottish singer Amy MacDonald has a hit album and is poised for major label success. Her secret, she tells Kevin Courtney, is to let music do the talking

Amy MacDonald is not that kind of girl. She's not going to pull a cheap publicity stunt just to score a hit record. You won't see her performing a gig in her flat and broadcasting it on the internet, and you won't hear about her breaking records for the number of friends she has on MySpace. The 19-year-old Glasgow woman is unlikely to be seen falling out of a trendy London club, her beehive in a mess, or picking a public fight with a musical rival. She hasn't even got a famous father, for goodness sake - although her dad did play the guitar before passing the instrument on to his eager daughter.

And yet, without any discernible gimmick or media angle - apart from the recent offer of a free download of her song Youth of Today, which she wrote when she was just 15 - her rootsy, folk-tinged debut album, This is The Life, has gone into the UK charts at number two, kept off the top slot only by the classical stylings of Britain's Got Talent winner Paul Potts.

MacDonald's voice is far from operatic - hers is a deep, sensuous burr, reminiscent of Nico, or maybe Melanie after a wild night on the town. It would appear that the record-buying public, having heard that voice on the jaunty singles Poison Prince and Mr Rock & Roll, liked what they heard and went out and bought the album. Simple as that.

"It's an amazing feeling," admits MacDonald, "and just to know that the UK public went out and bought the album, and I'm getting really good reviews and great feedback from them. It's just amazing, it's a great feeling." Perhaps the public were hooked not just by that remarkable, rich, voice, but also to the refreshingly uncomplicated sound, a jangly, upbeat style reminiscent of such 1980s acts as The Smiths, The Bluebells and Fairground Attraction. (Indeed, Ken McCluskey from The Bluebells was one who spotted MacDonald's talents while visiting her school as part of a community music group.) It may not be a perfect record, but it's definitely young at heart.

"It's back to the natural way of doing things - there's been no hype, because sadly I find that a lot of things in the charts are just hyped up, people are buying these albums because they've had them drummed into them."

With this album, you're not getting constantly bombarded with it - "if you hear it and you like it then you go out and buy it. So we've been careful not to hype it up, but to keep it very natural." There's little trace of those big, russet tones in her speaking voice - she sounds like just any other young Glaswegian as she talks about her musical influences, which include local heroes Travis, whose album The Man Who . . . spurred MacDonald to pick up the guitar and start writing her own songs, and Pete Doherty's old band The Libertines, whose spunky punk tunes woke up the rock 'n' roll rebel inside her.

"It's a shame that they're no longer, and that Mr Doherty has gone down the road that he has," she muses, in a voice that suggests she's been massively let down by her one-time hero turned tabloid puppet. "Well, musically I don't feel he's let me down, because it's a bit harsh to say that, but I think he's let himself down. He was such a power. He was an amazing songwriter and a great singer as well, and he's just squandered it just because he's got in with the wrong circles, and he's taking the rock'n'roll life a bit too extreme. It's just an awful shame, and I hope he'll start getting back to his roots and writing great songs again."

Born in 1987, MacDonald missed that golden age of Scot-rock, which saw the aforementioned Bluebells and Fairground Attraction, and also bands such as Del Amitri and Deacon Blue, delve back into the soil to come up with a more organic style of commercial pop, but she has it all on her iPod, along with the modern stuff and such swinging, soulful classics as Stevie Wonder and Frank Sinatra. When she picked up the guitar her dad had left lying around neglected, she found she could pull together enough chords to write a tune or two, but when she began to sing . . .

"I started singing and realised that what was coming out of my mouth wasn't that bad," she says with characteristic modesty. "It wasn't so much of a cat's choir, so I started to develop it a bit, and I just got better and better. I wasn't trying to sound like any other singer - I just opened my mouth and that's what came out."

By 15, MacDonald was playing gigs around Glasgow, under the supervision of McCluskey's community music group, covering songs by REM and Tears for Fears, but also adding in her own compositions. If you visited a Starbucks or a Borders book shop in Glasgow around then, you might have seen a teenage girl strumming her guitar and singing in a deep, mocha-flavoured voice.

Eventually, she progressed to playing pub gigs, sneaking into a local pub on Sauchiehall Street to take part in an open-mic slot. She also went to see Pete Doherty when he played in Glasgow, getting backstage to join in the singer's notorious after-show parties (but not taking part in the non-musical entertainment on offer), which inspired her to write the album's title track, This is the Life.

Another song, Barrowland Ballroom, aired her ambition to one day perform a gig in that iconic Glasgow venue. After sending out home-recorded demos to management companies and record labels, she got a deal with Vertigo and became labelmate to Razorlight and The Killers. She played a gig in Glasgow venue King Tut's Wah Wah Hut, and one review, while praising her "celtic roots mixed with indie-pop", suggested that, despite her big, brash voice, MacDonald might be a bit of a shrinking violet.

"I'm not shy on stage at all," protests MacDonald. "I don't know where that came from. It may have to do with the difference between my speaking voice and my singing voice. I kind of get a bit of verbal diarrhoea when I'm onstage, and going from that big, booming loud voice to this kind of quiet, sweet little girl voice might give the impression that I'm a little shy onstage." Another misinterpretation MacDonald wants to clear up concerns the song LA, which, she says, is not simply a musical fan letter to her all-time Hollywood hero, Jake Gyllenhaal.

"Actually, that's been taken quite a bit out of context. That's from my point of view - he's my favourite actor. But the way the song is, everyone has their favourite something, you have your favourite singer, others have their favourite football players, their favourite actors, TV personality or whatever, and they really like them and look up to them, but okay . . . these people are in your life to a certain extent, but you can always do things for yourself and you can be just as good as they are without having them there, if that makes any sense."

THE IRONY IS that, if the success of her album continues, there's no reason why she can't hang out in Hollywood with a Jake Gyllenhaal or two on her arm. Look at James Blunt, who, after the success of his debut album, went out and bagged himself a supermodel, Petra Nemcova.

MacDonald laughs at the ridiculousness of the idea. "I don't think so. I don't get recognised or anything, I'm not part of this whole fame bubble thing - I just live my life and hope for the best. I'm not into that tabloid thing - I didn't start playing music for the fame, which is a shame, because that's what a lot of people do, but it's just something which has never interested me. I don't think I would like to go down that route anyway, the boozing and the drugs and stuff."

What MacDonald is really looking forward to, though, is going out on tour with her band and playing the songs from her album. You can bet that by the time she starts her big UK tour in October, the fans will be singing back every word - although not in quite that same warm, compelling voice.

"That's the biggest part of this, where the most fun is. Playing every night has just been a pleasure, and the audiences have all been great. I'm happy - it's the reason I started doing this in the first place.

"Everything I've ever dreamed about has happened, so the next thing on my list - and we'll see which one happens first - is playing at the Barrowland or singing the national anthem at the opening of a Scotland football game."

This is the Life is out now on Vertigo