National Youth Orchestra / Macmillan, Roundhouse, London

Several firsts were celebrated here: the National Youth Orchestra's first concert of 2008; their first time working with the composer James MacMillan; and, amazingly, the first symphony concert to be held at the refurbished Roundhouse since it re-opened in 2005.

Time was when the Roundhouse, in all its splendid dilapidation, was the venue for contemporary work stretching from Boulez to Brook. It remains awe-inspiring architecturally but, alas, sanitised amid its cleanly sparkling bars and neon lights. Still, it is an unclassifiable venue in terms of product, so has no baggage to deter either the elite or the anti-elite punter.

And a packed-out house there was for the NYO, with from the sound of the coughs, cries and applause lots of parents and siblings of the vast army of youngsters playing their hearts out on stage. It is a sight to warm the chilliest of hearts.

I don't remember previously hearing an orchestra quite so large as this: octuple wind and brass, three tubas, five harps, 10 horns and strings to match. The Roundhouse is no state-of-the-acoustic concert hall, and ensemble was bound to be an issue with a band so vast. In the opening work, Britten's "Four Sea Interludes" from Peter Grimes, there were several moments when the front and the back of the orchestra almost became uncoupled.

Similarly, Prokofiev's dazzling score to his suite Romeo and Juliet was at times undermined by both acoustic and poor control from the conductor, who not only failed to make sure that everybody was playing together, but also provided little leadership in teasing out the extraordinary power and colour of this score. But then, no orchestra this size could be expected to provide precision performing.

In MacMillan's own Symphony, Vigil, written in 1997, the orchestra took on a daunting job. In this, the final part of a triptych, these youngsters were massively impressive, the Roundhouse proving superbly suited to a work needing antiphonal spacing for five brass players.

Turning round a programme of this complexity in 10 days is a marvel. The NYO is indeed an institution to be treasured.