Thomas Sutcliffe

I learnt earlier this week that Lily Allen is cool, which came as something of a shock to me, since I'd been enjoying her album in the mistaken belief that it was a guilty pleasure. I thought that it was one of those records you wouldn't quite own up to in the playground - if one still had a playground to go to. A little too Chas'n'Dave in its manner, perhaps, and somewhat touristically light-fingered when it came to musical influence. Apparently, though, the guilt wasn't necessary. Because here Allen is at number 3 on the NME's Cool List, bracketed by Jarvis Cocker and Faris Rotter of The Horrors (who sounds suspiciously like Private Eye's mythical rocker Spiggy Topes).

If I needed any confirmation that "cool" and I live on different planets, this was surely it; I'd taken a badge product and furtively tucked it out of sight inside my lapel. And frankly, I'm a bit worried about Allen's standing for next year's list - since my enthusiasm for a pop musician is usually an invariable indicator that their moment has already passed.

Cool is, in any case, the most fugitive quality of all - far more transitory than talent and far more vulnerable to sudden shifts in the wind. Indeed, more than that, it's one of those qualities that is inherently unstable, since it draws towards itself the anti-matter of the wrong kind of attention. The Arctic Monkeys were cool while internet downloads propelled them towards celebrity - but were they still cool after Gordon Brown claimed to have them on his iPod?

At the same time, it isn't impossible for cool to last - as we were reminded this week by the death of Robert Altman - a film-maker whose cool always remained remarkably steady despite the ups and downs of his career. (Ups and downs, incidentally, which weren't always evidence of the mercantile philistinism of Hollywood studio executives. One of the intriguing mysteries of Altman's cool is how it could have survived a film as bad as Popeye.)

Cocker, too, is an example of durable cool - though I suspect that he earned a Lifetime Honorary Membership with his awards-ceremony ambush of Michael Jackson - an act that demonstrated that very uncool behaviour (mooning) can sometimes be taken to such an extreme that it goes round the back and re-emerges as suave.

In fact, it's been a week in which quite a lot of things have been raising the issue of cool and its long-term maintenance. Take David Blaine, who this Tuesday set out to dangle above Times Square in a giant gyroscope. It might be hard to credit it now, but Blaine was very cool for a time - his heavy-lidded, doper manner being widely mistaken for a zen lack of ambition. In fact, it turned out that he'd just overdosed on self-importance, leaving him groggily incapable of seeing just how ridiculous he sometimes looked.

He is now, I would have thought, permanently beyond cool, which is virtually impossible to regain once it has been lost (cult status, which can be recovered, is quite different, because it almost always incorporates a sense of ironic detachment).

Altman, on the other hand, always rode out his downturns and disappointments, because of a refusal to admit that the verdicts of the marketplace (or of critics) really had any weight to them. Crucially, he did this not in a petulant way but with a shrugging insouciance about the vagaries of success. He somehow managed to imply that both his triumphs and disasters were largely accidental affairs, and that he could not himself easily distinguish between his best films and his worst.

That sense of independence from worldly evaluation is a critical component of cool - a carelessness, not about the work itself (passion and hard work are never inimical to cool), but always about its ultimate reception. But it doesn't guarantee that odd things won't happen.

This week I've also been reading Thomas Pynchon's new novel - whose work was at one time the very apogee of literary cool. These days, that verdict is more open to question but I don't think there's much doubt that the author himself is still cool - which must owe quite a lot to his decision to voice his cartoon appearances on The Simpsons, where he appears wearing a brown bag on his head and trying to inveigle passing motorists to pull over for an autographed photo. Making a joke of his own retirement from public display Pynchon acknowledges that reclusiveness can become a kind of publicity-seeking. In fact, he points to the indispensable centre of cool, which is not a feigned solemnity (which uncool people often adopt) but a well-maintained sense of the ridiculous. If Allen can avoid taking herself too seriously, she can easily survive the blight of my admiration.