The Eminem who makes his film debut in Eight Mile might be asanitised guardian of moral rectitude but the hip-hop star insists his debutfeature keeps it real about where he came from, writes Brian Boyd

Who's afraid of Eminem? Certainly not the $35 million worth of middle Americans who sat in the dark with him for two hours on the opening weekend of his debut feature, Eight Mile - a figure which recouped the film's entire costs in less than 48 hours. With the film and its accompanying soundtrack in with a bullet at the number one spots in both the film and music charts, it's a sweet victory for the controversial rapper, who was once memorably dubbed by George W. Bush "the most dangerous threat to American children since polio". The only threat being talked about now though is that to Marshall Mather's creativity - will Slim Shady going to Hollywood have the same negative artistic impact as Elvis joining the army.

A semi-autobiographical film about his trailer trash upbringing in Detroit, Eight Mile sees our hero living the American dream, updating the Rocky narrative for the hip-hop community and behaving with all the ideological

circumspection that is required of US screen idols. Watch as Eminem's character finds that "hard work" will necessarily "get him somewhere", see how living on welfare is viewed as being morally reprehensible and how those who work in minimum wage jobs are castigated as "losers". It's a film that will play well in the Oval Office.

But although Eminem's character is heroically displayed as honest, intelligent, a hard worker, a doting family member and even (in one scene) as standing up for a gay colleague who is being taunted, this is no star vehicle. Director Curtis Hanson came to the project with plenty of form (Wonder Boys, LA Confidential) and has created a vivid and authentic time-piece. With Eminem diligently subdued throughout, allowing a tarty Kim Basinger (as his mother) to steal the show, what impresses here most is how Hanson and cast have managed to present the hip-hop lifestyle (frequently misunderstood) and display its musical methodology to a mainstream cinema audience.

Once you get over the none-too-buried Saturday Night Fever/Rocky none-too-buried sub-text, you realise the film's strength is how it is bringing marginalised and impoverished inner-city American life to the multiplexes (MC Ken Loach anybody?).

The film's title refers to the real eight-mile boundary in Detroit which separates the black inner city from the white suburbs. Eminem plays Jimmy Smith, known to his friends as Rabbit, a young man looking for something better than his factory job and his life with his wreck of a mother in a trailer home.

Convinced his skills as a rapper offer him his "only shot", he joins up with a crew of DJs and MCs. The only white rapper in the area, he gets taunted as "Elvis" and "Vanilla Ice" and has to prove himself by "battling" - a rap gladiatorial "fight" where two people take to the stage and take turns to insult each other through "urban poetry" to the delight of the baying crowd. The overall winner of these "battles" will walk off into the sunset with a record deal. "Some people who saw my music videos approached me to act in films," says Eminem of how he got involved with the film, "but I always held back - because, you know, I'm not an actor - until Eight Mile came along and that was because it really, authentically showed what the hip-hop scene was like where I'm from in Detroit four or five years ago, which also was the time when I was coming up." To "keep it real", he brought the producer and director around to the places where he began his rapping career.

"Most every night there was a 'battle' on somewhere, on a Friday it would be in a place called The Shelter, then on Monday in a place called C Note it was interesting because what we were doing back then was very different to the New York and Los Angeles hip-hop scenes, we were like a mix of both, but a different world at the same time. So I thought that story would be interesting to tell".

The freestyling rap battles between the participants - the aim being to humorously humiliate your opponent by extemporising - form the centrepiece of the film's action. "Battling is so intense," he says, "I remember when I was doing it, it was like all these underground MCs trying to get a rep (reputation) from battling really well and that's how you got noticed and got a record deal, because you were skilful with words and rhymes. Whenever I lost a battle, it was like my world had ended - it's very difficult to explain to people not form the hip-hop world what it means - it's like the first time that Muhammad Ali got knocked out or something and the film shows this world that no one outside hip-hop circles really knows about.

"Anything can be used against you in the battles, they really go into your private life. If you're from a trailer park, they'll use that, if you're broke or if you're dumb, they'll use that, if you've dropped out of school - or even if you haven't dropped out of school - they'll use that, and my character gets the 'white' thing thrown at him. But that's what it was like in that Eight Mile area, it was a colour line between blacks and whites and it was nothing to do with income, you could both be equally poor."

Tipped for all sorts of awards glories, Eminem got so engrossed in his character that he even recorded the soundtrack album as Jimmy Smith. "I was scribbling away with a pen all the time, the only time I put it down was when they called "action", I was writing so much lyrics and new stuff because the film took me back to a time and a place, back to a time before I was Eminem, before I was anybody, and that strips you of all ego or whatever. I was writing as Jimmy, not as Eminem, not even as Marshall, that's how seriously I took it. Then I was rapping as Jimmy and you can hear that on the lead off single from the soundtrack, Lose Yourself.

"Throughout the film you hear Lose Yourself as a work in progress, Jimmy is trying to make it into something, build it into a song and at the end of the movie you finally hear the whole thing."

Also featuring the considerable talents of Jay-Z, Nas, Gang Starr and Xzibit, the Eight Mile soundtrack outsold Nirvana's greatest hits package on its first week of release and although the new Eminem songs here were written for a context they reveal a more reflective, mature rapper who seemingly has dropped grudges of old. The album also sees Eminem unveil proteges from his new own label, Shady Records, in the promising shape of Obie Trice and 50 Cent. Incidentally, unlike the Eminem records, there is no "clean" edit available of the soundtrack album.

For someone who is currently on probation for an unsavoury pistol-whipping attack, has been sued both by his mother and his ex-wife for "emotional distress", not to mention attracting opprobrium from gay rights groups, women's groups and George W. himself and being held personally responsible by some fundamentalist Christian groups for the Columbine massacre, he makes for a most unlikely celluloid hero.

Of future acting roles, he says "I'm not interested, but if the right opportunity comes along ", but you sense that as a clever cultural provocateur he's exploring the boundaries (something he's adept at) of how, and why, cross-over mainstream appeal runs contrary to the nature of hip-hop culture - wherein something is appreciated more if it has the ability to upset parents/moral guardians.

Or maybe he just now prefers to do what he does from inside the tent.

The Eight Mile soundtrack is out now on Shady Records. The film opens in Ireland in January