At the same time, the children who come to schools' matinées at the Royal Opera House are well-prepared by their teachers - something we'd all love to do when we go to a show, but which we often forgo for lack of time - and they don't come with the negative baggage of thinking that "something Great is something Boring". They take it as it is, and if everyone singing and playing gives of their best, and gives generously and authentically, they will be drawn into unselfconscious enjoyment.

Children as audiences of sophisticated artworks are one thing. The aesthetic use of the child, and of childish innocence, within complex works of art, is something which can make us uncomfortable, especially when, as in the performing arts, the children in question are actually present.

There is a sort of two-track process going on when rehearsing a piece like Britten's operatic masterpiece, The Turn of the Screw, a consciousness among the adult performers that while they themselves are engaging with intimations of depravity, the children have to be shielded from too much sense of what is going on. The same is surely true in the final scene of Berg's Wozzeck, in which a small child hears the news of his mother's death from a group of his friends - to the accompaniment of obscenely mocking woodwind - who then run off to view the body while he remains innocently playing. "Hop, hop," he sings.

Britten learnt more from Wozzeck than any other single piece - it informs the whole premise of Peter Grimes, the shocking focus on a poetic brute, and saturates The Turn of the Screw throughout. His deployment of the child's perspective throughout his oeuvre owes a huge amount to this devastating final scene, a far more interesting way of looking at Britten's artistic practice than shamefaced imputations of paedophilic scandal. In his War Requiem, a work as much about death itself as about war, we confront the implacability of death through the voices of children, who in their rough simplicity (singing low in the voice, somewhat gruffly) ask all too unknowingly, hence almost callously, for the souls of the faithful to be delivered from the pains of hell, the bottomless pit, the jaw of the lion. "Ne absorbeat eas tartarus, ne cadant in obscurum" ("neither let them be swallowed up by Hell nor fall into darkness"). Adult concerns voiced in childish innocence, a potent device.