PROMS NYO / Colin Davis RAH, London/ Radio 3

There's more than a dash of heroism about the National Youth Orchestra. It meets three times a year for intense sessions of playing that last a fortnight and culminate in concert-giving. Not just any old concerts of the kind of standard repertoire that orchestras always play, but rich, rewarding, brave concerts, programmed to feature unusual pieces or those that are often thought a technical challenge even to professionals.

None of the works in Saturday's Prom is other than central repertoire. The "Ritual Dances" from Tippett's opera The Midsummer Marriage and the Sixth Symphony of Vaughan Williams are key works of English 20th-century music. Sibelius's First Symphony, though less well-known than his Second and Fifth, is not unusual. It would be rare, however, to hear them played together in a single evening, despite the historical links between them. The "Ritual Dances" were first performed in 1953, only five years after the Vaughan Williams work. Moreover, by a touch of historical serendipity, the NYO, now in its 50th-birthday season, gave its first concert ever, opening the Bath Festival, on 21 April 1948, the very same day on which Sir Adrian Boult conducted the Sixth Symphony's premiere at the Royal Albert Hall.

For the Tippett, the orchestra surely had the best man for the job, Sir Colin Davis. He was giving his services free, an unusual gesture for a world-class artist, but one that suggests why admiration for Britain's most eminent conductor can only continue to grow. He knows how to pace this score, marshalling its sequence of vivid ideas within the broad rhythm of departure and return as the "Fire Dance" leads to the transfigured arrival of the opening music from Act 2 of the opera. The reading was notable for the resonant sound of four harps and cellos in agile unison in "The Earth in Autumn", for sinuous violas and fruity bassoons, plus perfectly phrased clarinet solos, in "The Waters in Winter", and for the madrigalian music for solo violins that other orchestras can find a sticking point - though not these players, who maintained a sizzling level of energy throughout.

In the Vaughan Williams, the setting was even higher. The NYO's seven trombones and six trumpets made the opening bitonal discord probably as loud as it has ever been, even in the cavernous Albert Hall. A four-in- one piece, written in the shadow of the nuclear age but never divulging precise meanings, it moved like an arrow from the opening bars to the Epilogue, marked by the composer to be played extremely quietly and without crescendo. Here, where the music suggests "our little life... rounded with a sleep", the composer, rightly avoiding further elucidation, says, "listen", and offers a gift of near silence. Davis's vision of the work was gripping and original. It would be good to hear it more often.

After the interval, the Sibelius took a while to get going, though once airborne it was full of insights. Fresh minds, fresh responses. To its manners and style of Finnish Tchaikovsky, the band brought total conviction. Like the VW Symphony, it ended in E minor, but defiantly. The difference was between forte and pianissimo, and half a century of war-torn history.

Concert repeated at 2pm tomorrow on BBC Radio 3