IT IS 25 years since Ronald - now Fr Ronald - Corp, with some noble helpers, founded the New London Orchestra: a vehicle for not just fine music-making, but for Corp's vision and courage in programming music that reaches beyond the staple repertoire. This the anniversary concert in St John's, Smith Square, in London, amply demonstrated.

Perhaps Corp's flair dates back to when he was a music librarian at the BBC; or perhaps he acquired this urge even earlier, when a teenager. But his audiences are the beneficiaries. With the arrival of the New London Children's Choir a couple of years later (their quarter-century jamboree is presumably to come), and several high-level choruses at his command, Corp widened the net even further. His recordings on Hyperion - the non-Gilbert works of Sullivan are a classic case - have opened the eyes of many of us. Those with the Children's Choiron Naxos - the electrifying "jazz cantatas" of Michael Hurd, not least (8.572505) - are models of their sort.

Corp (who also contributes reviews to these columns) is not just a proficient conductor, but a composer of note: cantatas, orchestral works, string quartets. A treat of this concert was to hear the first performance of Sinfonia 4711 - the numbers represent the dates of the late Bernard Pragg, a key helper of the New London venture, in whose memory this orchestral piece was written.

It is fun, clever, and jazzy in memory of the dedicatee, initially suggestive of a delicious, slightly medieval-sounding round, and - like a good and appealing sculpture, and all of Corp's fast-growing output - well-carved. Corp pairs instruments with interesting and ear-catching results; he uses time-hallowed devices in a fresh way; and, with his huge discography, he knows his light music: from the assured ease of this work, you might draw analogies with, say, Malcolm Arnold, or members of Les Six (Durey, the film composer Auric, and in the final chuggings here the Honegger of Pacific 231). The orchestra played like troupers.

There was much more; for the second half included works by two composers unknown to me, the innovative Max Richter, b. 1966 (a string piece of somewhat Nordic hue), and the delightful Albanian composer Thomas Simaku, now British and based in York, and the current winner of the Lutoslawski prize. His Plenilunio proved to be one of the pearls of a packed evening, before lighter fare such as The Teddy Bears' Picnic (John W. Bratton, 1867-1947, arranged by Frank Saddler, 1864-1921), whose structure and scoring frankly knocked everything else for six.

The moving heart of the concert was not so much the lovely opening Allegro of Tippett's nostalgic Divertimento on Sellinger's Round (the Irish melody "The Beginning of the World" from John Playford's later published collection The English Dancing Master, 1650-51), with its moving allusions to Purcell and Gibbons, but centred on Byrd's harmonisation of the tune itself. Rather, it was the elegy for doomed Europe: the Concerto for Double String Orchestra, Piano and Timpani by Bohuslav Martinů.

The elegy plays an importantpart in mid-European 20th-century music: in Mahler; in the grieving Concert Funèbre of Karl Amadeus Hartmann; in much of Frank Martin; or in Hindemith's plangent Walt Whitman cantata When Lilacs last in the Dooryard Bloom'd (also set by Roger Sessions). This also applies to Slavic composers: in Lutoslawski's Funeral Music, or here, in Martinů's aching, poignant slow movement.

In 1938, clouds were massing above Europe, nowhere more than over the composer's dismembered homeland, Czechoslovakia. The urgency of this orchestra's playing, and the intensity of Corp's direction, pounded home the grim truth.

For this masterclass in the expressive power of music, the ensemble was joined by a dozen players from four public schools: Wellington, Harrow, Oundle, and Dulwich. The enrichment of the sound by these young musicians was out of this world.