The Park Lane Group's annual winter concert series is an invaluable showcase for young performing talent. So why, worries Keith Potter, does it all sound so terminally middle-aged?

The unique attraction of the Park Lane Group's annual "Young Artists" series is its focus entirely on 20th-century music. This is self-evidently A Good Thing, even if one wonders how many of these young musicians will have the chance to go on playing contemporary music professionally after the PLG has offered them this platform. Standards of performance continue to rise, too; in the first three days of this week's 10-concert jamboree, I heard much playing notable not only for its accuracy and fluency, but for high levels of musicianship and sheer commitment.

Some selected players, indeed, are already established in the profession with a track record in new music. The flautist Rebecca Larsen (on Wednesday evening) had what you might call an effervescent platform manner, and abundant technical skills, but this didn't mean she always projected the music to best effect. She struck me as uneasy with Elliott Carter's demanding Scrivo in Vento and Thea Musgrave's over-extended Piccolo Play; she can't be blamed, though, for the awkwardnesses in David Bedford's new Oh Eva, Hear My Lament, which were, curiously for one so experienced, of the composer's own making. Her excellent accompanist was Juliet Edwards.

The night before, the cello-and-piano duo of Alasdair Tait and Jeremy Young - truly mature musicians - displayed prodigious, almost frightening levels of skill and commitment in Carter's Cello Sonata and Diana Burrell's evocative Heron (Bedford and Burrell are the series' featured composers); while, on Monday, the Boccherini String Trio (Amanda Smith, Jeremy Perkins and Nicola Baxter) gave us the chance to hear more of the notes of Iannis Xenakis's Ikhoor played more in tune than is usual even from specialists.

On Wednesday, a clarinet-cello-and-piano trio called the Emiro Ensemble (Sarah Miller, Charlotte Eksteen and Neil Roxburgh) brought consummate professionalism to a coherently planned programme of high-quality compositions, concluding with Piers Hellawell's Truth or Consequences, which integrates a dangerous range of materials into a compelling two-movement shape.

The saxophone-and-piano duo of Sarah Markham and Stephen de Pledge (Tuesday) also offered abundant musicianship, and true partnership, in rather limited repertoire. The accordionist, David Farmer, only 21, is another talent to watch; though, again, the pieces he played on Monday were frankly second- rate.

The playing I most sheerly enjoyed, however, came from the guitar duo, Mark Eden and Christopher Stell, a combination with even bigger repertoire problems. Their performances on Wednesday exuded such natural vitality and joy in their skills and rapport - I've rarely seen so much eye-contact between musicians - that I was hanging on almost every note of Michael Ball's meagre Music for an Island and Roland Dyens's protracted Cote Nord; Bedford's Verses and Choruses - a much stronger attempt at the same alternative formal design that had marked his flute piece - was a riveting experience.

So is everything in the PLG garden lovely? Well, not quite. The format seemed a mite jaded even 20 years ago; the skill and youthful enthusiasm of such players cannot alone dismiss the sense of an endless parade mounted with little feeling for the effect whole programmes may have on listeners. No wonder audiences still consist almost exclusively, it appears, of professionals, plus friends and relatives of the performers. There's a sense of complacency about the enterprise. And while at least a dozen pieces this season were by composers under 50, too many of these, and others, continue to be of that grey, middle-of-the-road, either vaguely post-tonal or vaguely post- 12-note kind that has been a speciality of too many British composers for far too long; the over-representation of one particular publisher doesn't help here. There's an awful lot of other kinds of new music out there of which the PLG seems unaware; if their selected performers' own submitted repertoire lists don't reveal some of it (which would surprise, as well as dismay, me), then the programme committee needs to go out and look for it. The "Young Artists" series must rejuvenate itself for the next millennium or it will surely wither and die as increasingly anachronistic.

The series ends tonight with programmes at 6pm (Glen Inanga and Jennifer Micaleff, pianos) and 7.30pm (Backbeat Percussion Quartet with Emma Murphy, recorders). Purcell Rm, SBC, London SE1 (0171-960 4242)