The central concert of the second weekend of the Barbican's annual Mozart event was given by the festival's resident ensemble, the Academy of St Martin in the Fields, under the increasingly prominent young Australian conductor Alexander Briger. Though not by any stretch of the imagination a period-instrument band, even the Academy these days shows an appreciation of the techniques and tone colours first explored by the early-music movement. But here their brash account of Rossini's Italian Girl in Algiers overture revealed such features on only partially assimilated display. Briger's dynamism offered little grace or wit, though a series of elegantly delivered woodwind solos added some corrective to an overly macho performance.

The orchestra settled down in Mozart's Clarinet Concerto, with the 16-year-old Julian Bliss as soloist. So accomplished is his playing from a technical point of view - with near perfect articulation of the fast passage work - that it is easy to overlook the fact that, as yet, it lacks strong character. Though he found an appealingly veiled quality for the reprise of the main theme of the slow movement, the finale was purveyed as mere entertainment, without any suggestion of ambiguity or depths still to be discovered.

Conversely, Adrian Brendel's account of the Haydn D major Cello Concerto in the second half of the programme offered a wider expressive range, with a distinctive quasi-vocal quality to the phrasing, but his intonation was patchy.

The concert's sole absolute success was the Jupiter Symphony, which Briger conducted impressively, boldly confronting the disturbing sections that periodically wrench the harmonic structure out of kilter, and leading the orchestra through the contrapuntal complexities of the finale. This is a piece the Academy must have played hundreds of times, but they have lost none of their relish for its blend of ingenuity and sublimity.