All was changed utterly, though, in the Concerto for Orchestra of 1963; the edginess and energy, even brutality, of King Priam marking a new phase in Tippett's stylistic development. With the orchestra divided up into discrete groupings on the stage, the gradual coalescence of the various strands of material into a grand collage was beautifully managed. What an original piece for a British composer to have written at the time, and how wildly avant-garde it must have sounded in Edinburgh 34 years ago. The brooding Lento reminded us that, for all its new hard-edged sound, Tippett's characteristic long melodic line was still at the heart of this music. The Concerto was dedicated to Britten, and amid the trumpet and percussion's echoes of distant wars in the finale, a haunting memory (is it a quote?) of the first "Sea Interlude" from Peter Grimes gave us momentary pause before the rondo impelled things to their abrupt ending.
The main work of the evening, A Child of Our Time - surely now a 20th- century classic - raised perennial questions: for the performers, of how to bring it all to life again, and for the audience, of how to hear the familiar afresh. It is a curious piece, with formal and stylistic influences ranging from Bach and Handel through medieval polyphony, to Stravinsky, Bartok and jazz. And then there's that libretto, with its mixture of the specific and immediate with the generalised and portentous.
The Festival Chorus managed some of Tippett's more tortuous syncopated fugues with dexterity and were thrilling in "Steal Away". A strong quartet of soloists delivered their sometimes odd words and angular lines with conviction - Ian Bostridge, by virtue of his age and his sensitive singing, was a particularly convincing "child". Some fast tempi made for a dangerous feel in places; the fact that modern performers can carry off these complexities at speed does not mean that they must.
There is something about A Child of Our Time - despite the problems of a musical language that is not yet fully integrated, a lack of dramatic momentum, and those slightly obscure, even cranky words - that creates a profound emotional effect. With the final glorious peroration - "I would know my shadow and my light", with its soaring solo voices leading into that most touching of spirituals, "Deep River" - one could feel a release of emotion in both performers and audience, reminding one that, for all its flaws, this is generous-spirited and great music. Laurence Hughes