The first concert by the 2008 National Youth Orchestra was also the first time a symphony orchestra had appeared in the Roundhouse since its 2005 reopening. Before a note was played, as the NYO's ever-enthusiastic audience settled into the auditorium's spacious informality, it was tempting to wonder what had taken so long. Moments later, as the players felt their way tentatively into Britten's Four Sea Interludes, it was clear: the flat Roundhouse acoustic does nothing for orchestral sound, and the layout makes coordination among an ensemble this large a challenge.

Still, by the final Storm interlude, the music's waves were beginning to crash. With Prokofiev's Romeo and Juliet suite, the orchestra found its confidence; the string runs were dispatched with a bravado professional ensembles might envy. The problem was that this ballet score just didn't dance, and that was down to the conducting. James MacMillan is a workaday stick-wielder, and the NYO deserves a maestro.

MacMillan's presence, though, had dictated the programme, or perhaps the other way around. His own symphony, Vigil, formed the second half. Built largely from slow-burn crescendos that break off into silence, it relies on effect rather than large-scale architecture, and as such worked well enough here. The duet for cor anglais and cello was beautifully played. But the work's 50-minute duration stretches scant musical material perilously thinly.

Perhaps the NYO players were inspired by working so closely with a composer. But I bet they are looking forward to getting back to the Barbican in April, under a full-time conductor.