Classical: LONDON SYMPHONY ORCHESTRA / PREVIN Barbican Centre, London

Sarah Chang is 14 but, like several other Far Eastern prodigy musicians, she looks even younger. For her Barbican appearance with Andre Previn and the London Symphony Orchestra she dressed to emphasise this - a tutu-like pink creation with matching shoes, the Sugar Plum Fairy to the life. But once the playing began, this all seemed rather peripheral. As a fiddler she is phenomenal: a commanding, round tone, shapely phrasing and technical security even in the most tortuous stretches of Sibelius's notoriously difficult Violin Concerto. The interpretation as a whole was musical, and the stage manner remarkably unshowy.

So why the faint but lingering discomfort? This is a very young talent. Whatever certain eminent musicians may have said, she isn't a "perfect" musician yet. Doubts won't be silenced: how much of the expression was authentically hers, and how much was the result of careful training? To be fair, what else would you expect from even the most gifted musician at 14, especially in a soul-baring work like the Sibelius? As long as she is not tempted to believe her own publicity, she could do really well. But that's a big if. The course of the star prodigy is full of such dangerous reefs and whirlpools; one hopes Sarah Chang has the luck, strength and sane guidance to steer her clear of them.

Chang's Sibelius was preceded by a something even rarer: a work written just over a decade ago which seems to have kept a toe-hold on the repertoire. Nicholas Maw's Spring Music has many of the ingredients of real popularity. It is recognisably a work of our times, but in essence the harmonic and melodic language is reassuringly familiar and warmly appealing. One might be reminded of John Adams, or of the earlier, friendlier Tippett seen through slightly frosted glass. All credit to Maw for giving in to the impulse to write it. Just occasionally, though, there's a hint that he might have retained the odd doubt about the exercise. One telling little melodic phrase kept sounding on the edge of turning into a big, long-breathed tune, but it never quite did, despite Previn and the LSO's generous efforts to assist it on its flight. It often seems that the thing today's composers have most difficulty with is singing - vocal or instrumental. Paradoxically, even some of the modernists of the Sixties and Seventies can seem lyrically freer than their accessibility conscious successors. The young Maw, who astonished the British musical scene with Scenes and Arias in 1962, could certainly do it. So why should he have run into difficulty in riper years?

Granted, melody can take many forms. There are few, if any, straightforward tunes in Ravel's ballet Daphnis and Chloe, but the work overflows with gorgeous lyrical invention. Previn and the LSO revelled in it, and Previn kept up the musical pace impressively - after all, Ravel did call this his "choreographic symphony". The choir-orchestra tuning went awry after the unaccompanied choral Pan interlude, but it's fiendishly difficult to keep this at pitch, and at least the LSO Chorus managed to stay in tune with itself here (no small feat). Otherwise their sung "oohs" and "ahs" were splendid. No question: however enjoyable the purely orchestral Daphnis suites may be, without the sound of massed voices something elemental is lacking. We got it here.