National Youth Orchestra/Davis, Barbican, London

Young blood revives old classics

Sibelius was aged in his forties when he composed his Third Symphony, and Elgar in his fifties when he wrote his Second. Both works tap feelings that ought to be beyond the emotional scope of teenagers and, yet, Sunday's Barbican performances by the National Youth Orchestra of Great Britain (part of their Easter Concert Tour) were as sincerely – no, as intuitively – felt as any that I've heard in recent years.

Sir Colin Davis was the head that unlocked the communal heart, smiling appreciatively at felicitous solos, lunging at the crest of a phrase or urging on climaxes like a man half his age. Indeed, it was a real joy to witness such spontaneous interrelation between the players and their conductor.

The Sibelius is a great wagon train of a piece where, in the first movement, strings build to a swaggering pulse while horns blare out behind them. True to form, the NYO relished every bar but the problematic second movement – which was taken at an unusually slow tempo – tested their powers of sustain to the limits.

Some view this music as dolefully Mahlerian; others as more fluid, even folk-like. Davis seemed to favour the first camp, with mixed results. The strings came off brilliantly, the woodwinds not quite so well, but the motorised finale (faster than usual this time) had a genuine sense of momentum.

Elgar's Second invited comparison with Davis's memorable live recording with the LSO. Sunday's reading was similar in outline but a little rougher around the edges. The symphony's opening was all driving energy, the second subject warmly arched and the development section never flagged.

It would have been easy for such generous forces to fall out of aural focus (the huge orchestra filled virtually every inch of the stage) but there were no significant lapses of ensemble, and the brass-topped climaxes of the second movement rang out in a way that Elgar surely intended.

It was there, in the Larghetto, that the NYO string bands were at their finest, especially around the central section, where, after the solo oboe had embellished the opening idea, the violins rushed in with an impassioned assertion of the second theme.

As on disc, the helter-skelter Scherzo harboured a deafening central catharsis, except that the NYO's brass and percussion onslaught was, if anything, even more ferocious. The finale held together well, particularly in the fugal episodes and in the glow of Elgar's Brahmsian closing pages. Once again, I was convinced that Elgar Two is on a par with the best symphonic Brahms – but, then, I had just heard a performance that fed my bias.

The audience's response to Davis was matched by that of the orchestra; indeed, it seemed as reluctant as we were to let him go. And, for once, we were grateful not to have an encore. Music that ends on such a serene farewell deserves the privilege of meaning what it says.