Just hanging around: When he's not playing with Dinosaur Jr, J Mascis is famous for doing nothing. Marek Kohn attempts to rouse the mighty sloth

There are those for whom sloth is deadly sin, and there are those for whom it is an animal whose lifestyle they aspire to emulate. Common sense dictates that these correspond with the winners and losers in life's race: all the more perplexing, then,

that the slack appear at present to be inheriting the earth. But when political gridlock and economic recession go hand in hand, the sloth's game plan doesn't seem so dumb after all. The grunge generation looks around and asks one radical, searching

question: Why bother?

Now that slack is smart, the leading lights of grunge are apt to be patronised by arbiters of fashion. Dinosaur Jr have been filmed shopping for grungewear by the BBC's Clothes Show; they have been cultivated by Matt Dillon, a fan of the band. Having adopted the term 'slacker' within moments of the appearance of Richard Linklater's cult film of that name, the British rock press has identified Dinosaur Jr's J Mascis as the definitive specimen of the type.

Mascis has also been retrospectively acknowledged as a pioneer of the grunge style, along with hardcore band Husker Du. It's certainly true that Dinosaur Jr - which basically means Mascis, who is the singer, writer, producer, guitarist and sometimes

drummer too - have been making the same kind of noise for some eight years. Dinosaur Jr has grunge the way that Otis Redding had soul. Viewers of Channel 4's The Word last week will have noted its obvious hallmarks: incredible volume, and guitar played without the mediation of any superego. Much of its appeal lies in seeming to be everything The Word so painfully is not: spontaneous, unpackaged, authentic, wild at heart.

Mascis himself shrugs off the idea that he is a seminal figure. As he is the first to point out, there is nothing new in guitar music. Suburban white kids pick up guitars, and the noise that comes out is grungey. They form bands because that is what

young men have done for as long as anyone can remember. Their fathers go to the office or go to work at the auto plant; being in a band is now the default option.

Most lack the sense of melody and the extra touches that distinguish Dinosaur Jr's music. In the midst of the maelstrom on the new album, Where You Been, chimes can be heard, initially incongruous but perfectly apt. Mascis also adds the thunder of timpani to the mix, making one wonder why hard rock has hitherto failed to take advantage of the most bombastic weapon in the orchestral arsenal. He was a drummer before he became a guitarist, as might be inferred from his soloing technique.

The treatment Mascis metes out to his guitar points to the true antecedents of the genre. The godfather of grunge, both in terms of guitar style and of wardrobe, is Neil Young. Its patron saint is Bart Simpson, underachiever superstar.

Grunge has become a broad church, embracing Nirvana's precision-engineered Nevermind album and Dinosaur Jr's plaintive tunes as well as the archetypal, heavy diesel guitar grind. Mascis inclines to a purist definition. 'Whenever anyone says 'grunge', all I can think of is Mudhoney, and whenever I hear Mudhoney, all I can think of is Blue Cheer,' he remarks, referring to an underground rock group of 1970ish vintage.

Musical considerations are only part of the reason J Mascis has become a cultural figurehead. He looks the part, on the basis that the frontman of a grunge band should resemble a roadie. And he projects sloth as awesomely as Brigitte Bardot projected sex.

The morning after The Word, the miasma of torpor has been enhanced by a rock 'n' roll night out. It has particularly affected bassist Mike Johnson, who normally handles most of the talking chores. Even under optimum conditions, however, Dinosaur Jr are probably uninterviewable in the conventional sense. They are not unfriendly; not impolite. There is no danger that J Mascis will flounce off or be seized with a fit of petulance, a perennial hazard in rock star interviews. But he refuses to play the game just as effectively, by chatting normally until faced with a question mark, at which point he feigns conversational death.

It's a subtle sign that Dinosaur Jr can't quite be integrated into the rock machine, as was their refusal to stop playing on The Word for a minute and a half beyond their allotted time. Passive-aggressive is a term that could usefully be applied to much of grunge. Instead of a rock 'n' roll sneer, Mascis favours an enigmatic smile. If he ever practised posing in front of the bedroom mirror he must have used the Mona Lisa rather than Mick Jagger as a model.

We talk, then, around the edges of an interview. It becomes clear that the pauses in the Mascis discourse are not due to analytical undercapacity. The impression is of a shrewd character studiously maintaining a distance from his surroundings. On the subject of live music, he speaks warmly of Richard Thompson's acoustic shows. We talk movies; he is parsimonious with his praise. On Singles, in which Matt Dillon plays a singer in a Seattle grunge band, Mascis is tersely diplomatic: 'Not his best work.' He detested Slacker, walking out after 20 minutes. As for Alison Anders' Gas Food Lodging, to which he contributed a discreet instrumental soundtrack and a cameo as a hippy desert rock-peddler: 'It was OK; it wasn't the best movie I've ever seen.'

What really fires him up is skiing. It was the only team he joined at school. 'All freaks, potheads, burned-out guys - my idols. To practise, we'd play frisbee and listen to Black Sabbath.'

In most respects, his curriculum vitae as a slacker is impeccable. He grew up in Amherst, Massachusetts, a town overrun by students, whose number he duly joined; spent some time at college in New York, emerged four years after enrolment without a degree, went back to Amherst. True, he was busy with the band, but the question remains: is he really lazy? Or is he just a beaver in sloth's clothing?

A very English sort of question, he observes, with a tart chuckle. 'I can't say that I'm lazy at this point.'

If not lazy, then laid back? Is it true, I inquire, that an engineer once remarked that Mascis handles crises by going to sleep? This turns out to be the first time he has heard the assertion. For some moments, I have only the fact that his eyes remain open to reassure me that he has not responded to the question in the same manner. He surfaces from the hiatus to explain: 'I'm just trying to envision a crisis in my life, envision going to sleep.'

Johnson interjects, helpfully: 'Like being on a freeway; car breaks down, crawl in the back seat and go to sleep?'

'Umm, yeah, I couldn't do that.'

Half a minute elapses, during which he reaches his conclusion: 'I'm not that laissez-faire'. In his way, J Mascis is indeed a pace-setter.

'Where You Been' is released on 8 Feb

(Photograph omitted)