There is no complete score, only parts, each performer free to decide what he or she wishes to play. The piano part has 84 different types of notation, varying from the standard to the abstract. Cage determined the notated music by chance operations and blemishes on his manuscript paper. The conductor indicates not tempo but a sort of variable metronome against which the performers measure their respective tempos. Needless to say, recording the Concert for Piano and Orchestra poses unique problems.

The criticism often made of post-Webernian pointillism – that it struggles to sustain interest over large-scale forms – is also relevant here. Sounds that, at the time, had a ‘wow factor’ of newness have since been naturalised. How, then, to render their impact anew? Philip Thomas and Apartment House, out of what could simply be a flat plane, render a vibrant surface with all the activity of a Jackson Pollock. Thomas’s touch is nuanced and various, a steady centre around which the ensemble’s ephemeral voices appear. This version is twice as long as the previous Wergo recording but the extended length allows one to enter in and out of the music.

The work is paired here with Resistance, an Apartment House commission by Cage’s erstwhile colleague Christian Wolff. Roughly the same length as the Cage, it contains quotations of left-wing material from Cornelius Cardew and Pete Seeger, and is by turns sprightly and humane where the Cage is drifting and cosmic. It is an apt pairing.