Given the catastrophic decline in instrumental tuition in this country, it's frankly astonishing that there are any youth orchestras left at all. Yet the London Schools Symphony Orchestra is still going strong. It gives three Barbican concerts a year, each preceded by intensive rehearsals held in the school holidays.

This autumn's concert under the able Peter Ash must surely have been one of its most venturesome ever: big scores by Strauss and Wagner, tackled with enthusiasm, verve and accomplishment.

It opened, however, with a suitably restrained and rarefied account of Debussy's Danse Sacre et Danse Profane, in which the string section provided an ideally delicate backdrop for the harp solo, played with assurance and style by the talented young Cecilia Sultana de Maria.

With Strauss's tone poem Death and Transfiguration, the magnitude of the challenge facing the orchestra was evident - perhaps occasionally just a little too evident. The opening chords were insecure, the tempestuous main section - admittedly a life-and-death struggle according to the composer's scenario - taxing the strings to their limits.

A selection of excerpts from Wagner's Gotterdammerung was scarcely less ambitious, but here the challenges were heroically surmounted. The sequence began with an evocative performance of the Dawn music, eloquent cello lines mostly moving together and alternating with well controlled low horns.

Fine clarinet and bass clarinet solos led, via impassioned love music, to splendid horn calls and a roller-coaster ride of a Rhine Journey. A noble Funeral March, with an impressively managed quartet of Wagner tubas heralded an excellent Immolation Scene, in which the soloist was Alwyn Mellor. Commanding of tone and consistently alert to verbal inflection, Mellor has huge potential as a Wagner soprano.

The orchestra responded magnificently, whether reduced to a sympathetic whisper or soaring confidently to its ecstatic conclusion.