Dressed down: Cusack in High Fidelity

He may have starring roles in two of the best films of the year and been hailed as one of the greatest actors of his generation, but as he ambles into the room it's clear the news hasn't filtered through to whatever passes for a wardrobe department in the John Cusack household. Bazza reports.

Celebrity camouflage for the streets of central London? Leftover props from his part as indie music obsessive Rob Gordon in his latest film, High Fidelity? Or just proof that Cusack is, as the legend growing around him suggests, so little fazed by the business of being a movie star that he will never, ever dress like one?

Dismissing the first and not recognising the T-shirt from the film, I'm edging towards the last. Before I can phone a friend, Cusack's own words bear me out.

''I was never interested in being an overly public person,'' he says. ''I think the more you expose yourself as a celebrity, the less interesting you are to watch in your work, because if you're putting yourself out there all the time, you're not holding anything back. And I've also seen the people who talk about their love lives in print invariably have doomed relationships with the person they're talking about.''

Which perhaps explains why Cusack is so criminally unforthcoming offscreen. No matter - his onscreen performance is the perfect atonement.

A fascinating actor to watch, he has brought a mixture of vulnerability and cruelty to his roles, whether as Craig Schwartz, the pony-tailed puppeteer in Spike Jonze's heroically strange Being John Malkovich, or Marty, the conscience-addled hitman in Grosse Pointe Blank.

The magic seems to lie somewhere in the interplay between his mouth (down-turned normally, but capable of the most disarming grin) and eyes which one critic famously described as having question marks in them and whose colour has been compared with Coca-Cola.

Facing him over a table, I scrutinise him with my own peepers (Irn Bru-colour, in case you're wondering). He's tall - six-three - and slim. Handsome, too, in that ''men can't see it, women can't miss it'' kind of way. Yesterday's five o'clock shadow, having dug in for the night, this morning blurs the lower half of his pale, oval face. The rumpled black hair, kinked backwards and sideway, is ruffled carelessly from time to time by a long white hand. (His, not mine).

Right now he's talking about the film of Nick Hornby's High Fidelity and its success in describing that strange psychosexual space which lies inside most thirtysomething men - the interface between girls, love and rare B-sides.

For Cusack, Rob Gordon is Everyman - albeit Everyman with a thing about early Smiths singles.

''I think that most males - most straight males, anyway - who read the book kind of see themselves in Rob - more than they'd like to, you know? I think most guys have been where Rob's been, maybe not as down-and-out or as poor, or as obsessive about music, but most guys have walked that path that Rob has and I think that's what made the book so great and so universal. And so universal for Americans too - he really gets inside the male mind in regards to matters of the heart.''

Helping with that universality for Americans bit is the fact that Cusack, who co-scripted the film with the Grosse Pointe Blank pairing of DV DeVincentis and Steve Pink, removed the story from Hornby's north London to his own stomping ground, Chicago.

Even the music has changed - while Hornby's paper protagonist was obsessed by American R&B, Cusack's version is a child of British punk, new wave and indie. Stiff Little Fingers, The Jesus And Mary Chain, Echo And The Bunnymen, The Clash and The Smiths are all namechecked, as are a host of 1990s bands. Scottish artists feature highly too, with Belle And Sebastian and The Beta Band mentioned by name.

In The Beta Band scene, Cusack surveys his shop and intones: ''I will now sell five copies of The Beta Band's Three EPs'', before playing Dry The Rain, from that album. ''They're the best new band I've heard in years,'' he says when asked how he really feels about the group. And Belle And Sebastian? ''I think Belle And Sebastian, if I'm not mistaken, is in the book.'' (He is. They aren't.)

''It was a perfect scene because Rob is very depressed and he goes into the store and Dick is playing this very soothing, melancholy music and then Barry comes in and breaks the space like a tornado.'' Barry's ''breaking the space'' involves shouting ''What is this shit?'' as the Glaswegians amble through Seymour Stein.

While the soundtrack is to be welcomed, the change of locale caused no small amount of grumbling this side of the Atlantic. Cusack is unrepentant.

''I know this might be shocking for a lot of British people but the transposition from England to Chicago was kind of effortless. When I read the book I knew where everything was in Chicago. I knew where the American Rob went to school and dropped out, where he used to spin records, I knew two or three different record shops when I was growing up that had a Rob, a Dick and a Barry in them.''

Stephen Frears, the film's British director, agrees. ''I thought it was a very good idea to set it in Chicago because it somehow takes a great weight off it,'' he says. ''I've spent a lot of my life getting out of north London - and it seemed to me that John and his two friends were writing a home movie about their lives in Chicago, which more or less paralleled Nick Hornby's life.''

Of course, director and star have something of a history. In 1990, Frears directed Cusack - then a precocious 24-year-old - in The Grifters, an adaptation of cult novelist Jim Thomson's story about a mother and son con team. With Anjelica Huston as his mother, Annette Bening as Cusack's slippery girlfriend and Martin Scorsese on voiceover duties, the film is viewed as a stone-cold classic.

It garnered Oscars for Huston and Frears, a Best Supporting Actress nomination for Bening, and it moved Cusack off the teen-flick list into the more fulfilling role of character actor.

It's a part he has played to perfection in many of the 45 films he's made since his big screen bow alongside Rob Lowe in the 1983 teen comedy, Class.

Born into an Irish Catholic family in the Chicago suburb of Evanston in 1966, Cusack's father, Dick, was an actor and documentary maker and his mother, Nancy, a teacher. His sisters, Joan and Susie are actors and Joan - or ''Joanie'' as he calls her - has a small role in High Fidelity.

Among the friends his parents brought home were Daniel and Philip Berrigan, two Jesuit brothers who later served time in prison because of their activities as peace protesters. Their exploits included breaking into an army office during the Vietnam war and burning draft papers and, more recently, trying to dismantle a warhead. Daniel Berrigan now works in an Aids hospice in New York.

So although governed by his parents' devout Catholicism, Cusack's was an unconventional, free-thinking childhood. No surprise, then, that he turned to acting via Chicago's Piven Theatre Workshop, run by the parents of one of his friends.

Bit parts in adverts lead to bigger and bigger film roles (in Rob Reiner's The Sure Thing, John Sayles' Eight Men Out) until Cusack hit the 1990s running with The Grifters.

So how did Stephen Frears feel teaming up with his protege again after a decade-long gap? ''I was shocked he didn't still call me 'Dad','' he deadpans. And does he go along with the views of British director, Mike Newell, who found Cusack a little too quick with his mouth on the set of Pushing Tin?

''I had experience of that,'' he says. ''They're buggers, Americans. They ask questions. They're not servile and grovelling like the English are.''

Whatever the reasons, the film works. The celebrity cameos - Tim Robbins, Lisa Bonet, a ''pre-Douglas'' Catherine Zeta-Jones and, in a bizarre dream sequence, Bruce Springsteen - certainly help, but mostly it's the relationship between the three men which provides the film's comic engine. It's a fact reflected in the constant exclamations of ''Oh my God, that's my life'' from most male audience members.

Jack Black, as the boorish Barry, is a revelation, as is Iben Hjelje as Laura, the girlfriend who walks out on Cusack early in the film.

Frears ''found'' Hjelje at the Berlin Film Festival where she starred in Mifune, one of the Dogme95 films. He says: ''I just went up and talked to her and I think she thought I was some sort of white slaver.'' Until then, he had despaired of finding the right woman to partner his star.

''If you look at the book a different way,'' he continues, ''the girl leaves him on page one and all he does for 250 pages is go on about her [a pretty fair summation of the film too, as it happens]. That's completely obsessive love. So you think 'Blimey, the woman who's going to make this bloke go on for 250 pages must be something special'.'' And after all that chasing, does he end up getting the girl?

Well, he is John Cusack, after all. Even if nobody's told his wardrobe.