Why do critics get so hot under the collar when it comes to concert clothing?

Jessica Duchen says it's sartorial snobbery

Shock of the new: Yuja Wang was criticised for wearing a short, tight-fitting skirt at a recent recital

Why can't classical music just get over itself when it comes to concert clothing? You'd think that The New York Times would be above such concerns as a woman musician's side-slit skirt and shiny stilettos. But apparently not. Recently, Yuja Wang, the 24-year-old Chinese virtuoso – the pick of the bunch among today's finest young pianists – gave her debut recital at Carnegie Hall. While the critic praised her "delicacy, poetic grace and attention to inner musical details", he also felt obliged to comment on what she was wearing.

That's because this summer Wang made waves in the classical world by appearing in an off-the-shoulder orange dress for a concert at the Hollywood Bowl – "so short and tight that had there been any less of it, the Bowl might have been forced to restrict admission to any music lover under 18 not accompanied by an adult," quipped the Los Angeles Times. For Carnegie Hall, Wang wore suitably sober black, though for the second half, The New York Times tells us, she changed into a dress with – ooh, a long split up the side.

Wang herself takes a dim view of the fuss over her attire. "It's ridiculous," she says. "As an artist I think I have the freedom to wear what I like as long as it looks good. I'm 24 years old, and at this age I hope I can wear whatever I want. After the Hollywood Bowl concert they were commenting on my short skirt – but I'm a short person! I wear what fits me. And it was the Hollywood Bowl [a comparatively fun, informal venue], not La Scala, Milan. People can think what they like, though I find it a little sad if they're talking about my dress more than my playing."

She's right, of course, as any reality check beyond the classical bubble can prove. Over in pop music, that orange dress might seem staid. Rihanna's recent under-clad adventure with an outraged farmer when filming in the fields just wouldn't happen to a classical musician. Wang's miniskirt didn't look as if she was doing anything more risqué than nipping out on Friday night for a few vodka and tonics plus dinner at Gordon Ramsay. A good many of today's pop performances, replete with breathiness, pouting and acres of waggling flesh, are barely an inch away from watered-down soft porn; Rachmaninov piano concertos have a way to go yet.

A row is also bubbling up at the moment about suitable concert clothing for orchestras. The other day a young viola player wrote to a fashion columnist for advice on what his orchestra should wear on stage. Some concert-goers parrot the view that penguin suits should have gone out with the Titanic. Not a bit of it, came the response: tails are much classier than all-black.

That might come as a surprise. Still, she had a point. Why should orchestras look like stagehands when they could be in white tie and tails, the garb of guests at an imperial ball in Vienna? Orchestras need to appear as the unified teams they are; it would be fine for them to ditch evening suits if anybody had actually found anything better. Colours are messy; all-black is grim and uneventful; and if they don white dinner jackets they look a bunch of wine waiters.

The Budapest Festival Orchestra got it right at the Proms this year. They wore conventional concert clothes for their Mahler symphony, but for their late-night Prom – an informal "Audience Choice" event, with solo spots for small groups of players – they went casual. For Mahler, casual dress would have missed the point. It's a hefty, intricate, tightly wrought piece in which the orchestra has to function as a perfectly integrated machine. They should look like one as well.

It would be nice, though, if they could also look like artists. Occasionally, one of them scoops sponsorship from a designer label to excellent effect, at least for the women. But you can bet that eventually one dissenting member will propose that all flesh should be covered on stage, or a conductor will complain about exposed batwings (Leonard Slatkin once caused much fuss in a tabloid newspaper by doing just that), and it's adieu to concert chic.

Soloists are individuals by definition – so where does that leave Yuja Wang and her short or split skirts? The point, surely, was the music? Yes – and by all accounts, she played wonderfully at both Carnegie Hall and the Hollywood Bowl. The best concert clothes are tools of a trade. Comfortable, packable, personal, practical, expressive, they're essentially outfits for work. Chances are that the orange dress fulfilled all those criteria, in its own minimal way. The trick is to wear something that looks good, makes an impression and makes sense.

The great pianist Mitsuko Uchida looks stunning in velvet trousers and translucent silk jackets which she says suit her practical needs. Anne-Sophie Mutter's favoured look is strapless dresses which leave the shoulders and arms free to control violin and bow unencumbered by puffs or straps. And intriguingly, the young pianist Alice Sara Ott likes to perform barefoot; apparently it increases her sense of contact with the piano's pedals, which control the resonance of the sound.

Male musicians have jazzed up their outfits too. Many choose round-collared Nehru jackets instead of tailcoats; some credit their suits to top designer labels; and the pianist Jean-Yves Thibaudet has been known to commission outfits from Vivienne Westwood, while Lang Lang sometimes raises hackles with his sparkles.

But the prize for the worst concert outfit I've seen goes to an inexperienced musician whose name I forget, giving her London debut in a short, tight-skirted, strapless dress that didn't fit too well. The top kept requiring urgent mid-sonata readjustment. As for the skirt – unfortunately, she was a cellist. At least a pianist doesn't have to hold her Steinway between her knees.

The job of concert clothing is to help the performers produce their best efforts, moving easily and feeling good in the limelight. And if a musician plays as fabulously as Yuja Wang does, we shouldn't really watch anything except her amazing hands.