London Sinfonietta/Masson/Bailey, Royal Festival Hall, London

The build-up was impressive. "A revolution in the way that we are being asked to listen, which is wonderfully freeing," promised Marshall Marcus, Southbank's head of music. And so a capacity audience settled down to meditate its way through the British premiere of Prometeo by the late Luigi Nono.

Subtitled "A Tragedy of Listening", this uses a text by the Venetian philosopher Massimo Cacciari apparently treating the Prometheus myth as an emblem of freedom and democracy. Apparently – because very little of it proved audible, much of it being written into the players' parts for them to think about. The singers and players were disposed around the hall in many groups, controlled by two conductors often beating unrelated tempi, their sounds further mixed and projected around the space from an electronic console presided over by Nono's associate André Richard.

If the set-up was reminiscent of some of Stockhausen's grander efforts, the sound world of Prometeo proved quite different; nor, a few jagged brass outbursts apart, did it have much of the searing fierceness of Nono's own earlier serial and protest works. Most of it is sparse and quiet: a solo voice chanting a word or two, a fragment of choral texture broken off, a few sustained notes here and there against barely audible drifts of string clusters, many long pauses.

For the vocalists of Synergy and the players of the London Sinfonietta and the Royal Academy of Music Manson Ensemble endlessly counting their silent bars between their few notes, for their two conductors, Diego Masson and Patrick Bailey, as much as for the audience itself, the effort was to hold on to, to make sense of a music that seemingly refused to lead the ear, to accumulate, to achieve any sense of climax or closure.

And yet, through the work's disparate sounds there was a kind of austere continuity to be discerned. As the entire structure finally resolved on a bare fifth, one had the touching sense of Nono making his peace with the great European musical heritage he had spent so much of his career questioning and trying to revolutionise.