She raps about tough subjects but it's her bittersweet acoustic sound that makes new Mercury prize-winner Speech Debelle stand out from the crowd, writes JIM CARROLL

THE FIRST THING you’ll hear on the debut album from Speech Debelle is a softly strummed acoustic guitar. While a wave of breezy, laid-back beats is not far behind, that bittersweet, gentle acoustic sound is a huge part of this album’s appeal – and it’s certainly something which should not be overlooked when it comes to assessing the rapper and her album.

As a result of Debelle walking away from London's Grosvenor Hotel with the Mercury Music Prize gong and a cheque for £20,000 on Tuesday night, many more people will be checking out Speech Therapyin the coming weeks and months. What they hear may well surprise them, especially if they're expecting a straight-up hip-hop record.

Released in June, Speech Therapyreceived hugely positive reviews from the critics, who praised the 26-year-old south London rapper's emotional honesty, silky voice and her album's beautifully honed sounds.

Debelle's striking tales of family unhappiness ( Daddy's Little Girl, for example, is about her absent father), of life on the edge and of general social unease make up an album that would stand out in any pack you care to mention.

While Debelle has been writing lyrics since she was 13 years old, her songcrafting became more focused in her late teens.

At that stage, she was living in a hostel, having been thrown out of home by her mother after one argument too many. “I was very alone and isolated in the hostel because I was so young and scared, so the writing became a way for me to keep my sanity,” she says. “The writing became my life.” But Debelle is no overnight success story. Between writing the initial songs over six years ago and releasing the album, she tried to get various music industry hustles off the ground, though none ever succeeded.

Eventually, Will Ashon at UK hip-hop label Big Dada gave her a record deal and producers Wayne “Kotek” Bennett and Tunng’s Mike Lindsay began working with her on the album’s warm, jazzy, folky beats.

The folky sweep of those sounds is a reminder that Debelle certainly didn’t intend her debut album to be merely another hip-hop release. “I wanted the album to be like Tracy Chapman with very stripped-down melodies, but with heavy lyrics and themes”, she said before its release.

“Another big inspiration was Meshell Ndegeocello. I wanted to create an album that would really take people somewhere like she does and trigger certain emotions in the listener. And I liked the idea of getting some Coldplay melodies on there too.” All of this means the album is a strange one in hip-hop terms. As a genre, hip-hop rarely has much space in its ranks for the vulnerable and sensitive.

These are qualities which most rappers tend to keep well hidden for fear of being seen in some way by their peers as weak.

Many, though, will use tales of childhood disadvantage to explain their drive and ambition to succeed and get ahead. Be it 50 Cent or Eminem, a tough childhood and the desire to escape the ghetto is always cited as an inspiration for their work.

However, Debelle’s chronicles of her difficult upbringing don’t come with a similar message about getting out and getting on. Instead, like a very skilful narrator, she simply recounts and relives her experiences.

Debelle’s sound, too, is out of kilter with current fashions in both US and UK hip-hop circles. Across the Atlantic Ocean, the majority of mainstream releases are buffed and polished with a synthetic, over-processed shine.

If an acoustic guitar is used in the studio, it’s usually buried in the mix or merely used for the token ballad. Debelle’s use of clarinet would probably be viewed with great suspicion. As for the lyrical stance often taken by female rappers, it’s safe to say that Debelle is unlikely to be seeking to emulate the sexual frankness of Eve or Amanda Blank on her next album.

In Debelle’s native land, hip-hop troopers largely come from the grime camp, as has been the case with previous Mercury winner Dizzee Rascal, Wiley and current pop-rap star Tinchy Stryder. Others tend to be more idiosyncratic characters like Debelle’s label-mate and album guest Roots Manuva. Few of them, probably, would even recognise Tracy Chapman, let alone own up to her as a guiding light.

But Speech Therapy is probably all the better for not following a tried and tested hip-hop formula. After all, this is what appears to have caught the attention of the Mercury Music Prize jury.

“The thing I love about this record is that it is a rap record that doesn’t sound like a rap record”, said music critic Jude Rodgers, a member of this year’s judging panel. “It brings in many influences, from jazz to folk and blues, even old TV soundtrack music. It’s very British, which I think is wonderful.

“It does present a real freshness and individuality.” Given that the album had sold less than 3,000 copies before this week’s events, Debelle will now be hoping that such “freshness and individuality” leads to a sizeable sales bounce.

Speech Debelle plays Belfast’s Stiff Kitten on October 2nd and Dublin’s Academy 2 on October 3rd

PRIZE FIGHTERS

THE MERCURY PRIZE, awarded since 1992, has often been given to new or non-commercial acts, and pits different genres against one another, ranging from folk and jazz to hard rock. The winner gets £20,000, (€22,743.75 ) though the boost from album sales can be worth much more. The award, made by critics and industry figures, focuses on the music -- it doesn’t take into account sales, media exposure or live performances

BOOSTED

Among the acts given a fillip by winning a Mercury Prize are rapper Dizzee Rascal (real name: Dylan Mills), who won in 2003 for Boy in Da Corner, and Badly Drawn Boy (aka Damon Gough), the 2000 winner for The Hour of Bewilderbeast. Last year's winner was Elbow's The Seldom Seen Kid, whose sales surged sevenfold on the news. Klaxons won in 2007 with Myths of the Near Future(Polydor).

BUSTED

Previous hit albums that were nominated for the Mercury Prize but failed to win include Robbie Williams's Life Thru a Lensin 1998, when the award went to Bring It On, by Gomez, and OK Computer, by Radiohead, in 1997, beaten by Roni Size/Reprazent's New Forms.

TALKING IT UP

“Speech Debelle can look forward to a big surge in interest, and the sales that come with that,” says Martin Talbot, of the Official Charts Company. “It is one of the least established albums in the history of the Mercurys and still has great potential.”

Speech Therapy, released in June on the Big Dada label, has sold fewer than 3,000 copies, half of which have sold since it was shortlisted seven weeks ago. Debelle has never reached the Official singles or albums charts, although that should change, following the win, Talbot said.