Gala Concert, Cheltenham International Festival of Music, Cheltenham

This year's Cheltenham Festival opened amid a riot of anniversaries. It's the 60th festival, Michael Berkeley's 10th (and last) as director, Birtwistle's 70th birthday, Holst's 130th, and so on and so forth. All this can get a little wearing and arithmetical - for instance, totting up the English composers who were born or died in 1934, or charting the 60 new works in the 71 events over 17 days (that's 4.176 events and 3.53 premieres a day). But luckily, a concert is still a concert, even when it takes place on the 4 July without an American work in sight.

This year's Cheltenham Festival opened amid a riot of anniversaries. It's the 60th festival, Michael Berkeley's 10th (and last) as director, Birtwistle's 70th birthday, Holst's 130th, and so on and so forth. All this can get a little wearing and arithmetical - for instance, totting up the English composers who were born or died in 1934, or charting the 60 new works in the 71 events over 17 days (that's 4.176 events and 3.53 premieres a day). But luckily, a concert is still a concert, even when it takes place on the 4 July without an American work in sight.

Berkeley's tenure has been, beyond question, a brilliant one. He has reasserted the festival's new music credentials; he has brought back to this beautiful but slightly somnolent town a real, as opposed to spurious, sense of musical contemp-oraneity; and he has surrounded even the stickiest events with an air of conviviality.

Sometimes the effort might seem a little forced. Swivelling the Town Hall sideways, as he did for Sunday's gala concert by the London Sinfonietta under Pierre-André Valade, and having an announcer interview composers (semi-audibly) while the platform is reconfigured, recalls nothing so much as the old BBC concerts, where every five minutes of music entailed 10 minutes of scene-shifting. But then, maybe the allusion was deliberate. Several aspects of the Sinfonietta's programme suggested a certain nostalgia for the palmy days of Musica Nova, with its themeless micropolyphonies (Ligeti's Melodien), its mindless repetitions (Zoltan Jeney's Heraclitian Fragments, actually a newish piece), its twittering mechanisms (Birtwistle's Carmen Arcadiae, written for the Sinfonietta's own 10th anniversary, and a work I still find irresistible).

The new music of the Berkeley age is not quite in this apostolic vein, though it pays its homages. In Sunday's concert, both Tansy Davies's Iris and Berkeley's own Double Guitar Concerto cast their net beyond the asperities of the palaeo-modern era, but by no means rejected them out of hand. Iris, a saxophone concertino (soloist Simon Haram) named after the Greek goddess of the rainbow, draws fruitfully on certain types of stylistic confrontation that go back at least to the early Seventies, when Davies herself was actually born. Brilliantly uninhibited wind and semi-pitched percussion sonorities form blocks against the soft background of a slightly rancid string chorale - the very description evokes memories. Yet the music is entirely individual, vivid, and above all acutely "heard." Even in the murky acoustics of the Town Hall, the detail sang out.

Berkeley's concerto was less fortunate, its intricate inner voices vanishing into the air, and the twin guitarists often barely detectable as soloists, even though amplified. Whether it was the medium or the environment that got the better of them remains to be seen.

The Festival continues to 18 July (01242 227979). This concert will be broadcast on Radio 3 on the 17 July