National Youth Orchestra/ Bychkov, Symphony Hall, BirminghamPark Lane Group Young Artists, Purcell Room, London

A crash course for young musicians of 20th-century music and ideas resulted in a beautiful journey

Mahler, Beckett, Lévi-Strauss. Bach, Stravinsky, Ravel, St Anthony of Padua, Dr Martin Luther King and, for three nights only, in Birmingham, Manchester and London, Mr Semyon Bychkov.

It is difficult to imagine a more provocative and demanding crash course in 20th-century music and ideas for the National Youth Orchestra's January programme than Luciano Berio's glorious babel-tower of poetry, politics and music, Sinfonia. Add to this the perilous inclines of Strauss's Alpine Symphony, and a work conceived in improvisation workshops with composer-conductor Peter Wiegold, and you have an experience that will have expanded the musical imaginations of 160 teenagers. From Bromley to Bridgend, Abingdon to Ormskirk, the ranks of the avant-gardists have swelled.

The NYO has been running for more than 60 years now. After decades of cuts in musical education, it cannot challenge the Venezuelan El Sistema, and it was troubling to see that the number of non-white players is currently lower than that in the City of Birmingham Symphony Orchestra.

I doubt that I will ever hear Berio's O King performed by a melting-pot orchestra, though there was at least one instance of instrument-spinning in Wiegold's Bow-Wave. Local youth orchestras continue to chip away at the social divides while the NYO makes the best of what it has, stretching musical, if not demographic, limitations. And who better than Bychkov to belay the young climbers in the Alpine Symphony and guide them through Sinfonia's eclectic mash-up?

If the Strauss narrowly failed to "make tulips grow in my garden" (as promised by Ben Parry of London Voices in Sinfonia), it was nonetheless one of the clearest journeys through this work that I have heard. Bychkov's clarity of gesture, intellectual rigour and intimate understanding of the topography of the Alpine Symphony made this sometimes sublimely silly piece properly sublime. The intonation was blurred but the dazzle of the sunburst and conflagration of the thunderstorm blazed. Led by Michael Foyle, the reduced string sections were sensitively blended, while Melanie Rothman's oboe solo revealed startlingly mature musicality. Here, and in the Berio, Bychkov's task was less one of shepherding technical insecurities than of overcoming the players' inhibitions, and it was fascinating to watch hesitancy yield to animated engagement. Sixty years young, the NYO remains a source of inspiration.

Founded in 1971, the Park Lane Group is a relative whippersnapper. Annually it presents 10 concerts across five evenings at the Purcell Room, showcasing young artists in a repertoire guaranteed to prevent a run on the box office. The quality of the performers remained extraordinarily high in the first of this year's concerts – violinist Sulki Yu delivered mesmerising accounts of three of Salvatore Sciarrino's fricative Capricci and Edwin Roxburgh's rhapsodic Soliloquy 3 – but PLG's programming is kinder to the British composers who make up an unusually high proportion of its audience than it is to anyone else. Cellist Pei-Jee Ng's performances of David Matthews's Journeying Songs and Daniel Kidane's Metamorphosis were strong and expressive, but I failed to warm to the sucking, fluttering, wheezing and whimsy in Consortium5's performances of Darren Bloom's Consorts and Kathryn Butler's Cassiopeia, or the Ronnie Hazlehurst tweeness of Daniel Bickerton's The Court Jester. Chaste in the Actus Tragicus, enchanting in The Fairy Queen, the sound of recorders in consort is charming, but not infinitely so.