Allegri String Quartet, Wigmore Hall, London<br></br>Park Lane Group Young Artists, Purcell Room, London

Something old, something new, something missing too

If music is ever-changing, much the same can be said of the way in which it is performed. Thirty years on from the first snapped hemiola of the early music movement, a Pastoral Symphony played by the Philharmonia has more in common with that of the Orchestre des Champs-Elysées than it does with Stokowski's soundtrack to Fantasia. What started out as a backyard business has become near-ubiquitous in its influence: not just in orchestral playing, not just in older repertoire, but in chamber music, choral music and opera. Pity the musician whose luscious legato obscures structural clarity. But pity too the authenticist who plays his gut strings in a 1970s style. Now we want it all.

But what of those ensembles and individuals who have resisted the hypnotic lure of historically informed performance practice and its modish parentheses, commas and semi-colons? In some quarters, they are held as the link to a golden age, though no-one can agree on when this golden age was. The keenest of ears might trace an inflection back through several generations. Listen to Renaud Capuçon and the presence of Isaac Stern still reverberates, and, after that, the faint perfume of the 19th-century emigrés that taught him to play the violin in 1920s San Francisco will hang in the air. But strong as these family ties inevitably are, time moves on.

Today's Philharmonia might not sound much like the Philharmonia of 50 years ago: there's more clarity in the brass, more piquancy in the woodwind, a tendency to tighter articulation and a good deal less generalised vibrato. Look at the players and some will be young enough to be their desk-partners' children. Yet it's still the Philharmonia, just as Manchester United is still Manchester United. Can the same be said of a string quartet? And at what stage does a new generation of musicians force a break with tradition? In the case of the Allegri String Quartet, whose reputation was founded on performances and recordings made when three of its members were barely a twinkle in their daddies' eyes, the fracture is imminent. Much as the audience at their 50th anniversary Wigmore Hall recital might dearly love them to be memorialised as golden-agers - which, after 25 years in the quartet, their first violinist Peter Carter probably already is - it's make or break time for this illustrious ensemble.

So, three players in their thirties and one of nearly 70. It's a style thing, right? Not quite. It's a sound thing, a rhythm thing, a phrasing thing, a balance thing and a language thing. If the cool, concentrated, wordy playing of Dorothea Vogel (viola) and Rafael Todes (second violin) leans towards early music sensibilities - with vibrato used as an expressive device rather than some form of water-proofing agent - Carter's slippery warmth harks back to the emulsified sound of pre-war chamber music. His tone has a kind of antiquated, calorific beauty; oddly consonant-free, to my ears, in Haydn and Schubert but undeniably lovely when cooled down for Britten's elegaic figures. Unfortunately it forces their cellist, Pal Banda, to act as a bridge between two musical cultures: sumptuously long-legged of tone, oddly clipped in his phrasing and confused as to whose sound he should be blending with. When the three separate styles of the Allegris cohere - as they did in Britten's Third String Quartet - the shimmer and grace and intelligence of this ensemble is riveting. When they fight and fragment - as in the first and final movements of Schubert's Death and the Maiden and in the final movement of Haydn's Sunrise - it is a terrible mess. But a duo and two soloists are not, really, a quartet at all.

Still, there's something to be said for a capacity audience these days. Could Schubert, Haydn and Britten have anything to do with it? I think so. Which makes it doubly frustrating that that other great British post-war musical institution, The Park Lane Group, should stick to their self-defeating policy of making young artists play programmes exclusively dedicated to contemporary music in the quietest week in the musical calendar.

As a means of promoting promising players and singers, PLG's Young Artists Series is rigidly Reithian: all atonal stick and no diatonic carrot. Give or take a few composers, friends and relatives, their audiences are consequently the tiniest imaginable; making even the Purcell Room feel large. Worse still, after a blisteringly athletic solo recital of very similar works by Boulez, Whitmarsh, Firsova, Hesketh and Cashian - all unknown to me barring Boulez's Incises (2001) and horribly reminiscent of that scene in Green Card where Gerard Depardieu pretends to be a composer and improvises on the keyboard - I have absolutely no idea how good a pianist Daniel Becker is. Would a tiny bit of Beethoven hurt? A mere Bagatelle? Given PLG's track record in talent-spotting, chances are that Becker is a smashing performer. But I would have enjoyed the opportunity to find this out for myself.

Matters improved in the second of Tuesday's showcases, which was shared by The Aurora Ensemble, soprano Anna Dennis - whose insouciant presence and gutsy high register outshone much of her material - and her excellent accompanist John Reid. The Aurora Ensemble played Carter and Kurtag's Wind Quintets with complete professionalism - tight, witty, beautifully balanced and cleverly phrased - while Dennis and Reid's performance of Kurtag's Requiem for the Beloved was voracious, tender, blanched and desolate: qualities they also brought to the premiere of Elena Langer's exquisite Late Autumn Lullaby 2. Another golden age in the making? Quite possibly.

a.picard@independent.co.uk