In the instance of Como una ola de fuerza y luz (1972), the notion of a piano concerto became combined with a memorial to the Chilean activist Luciano Cruz in a piece whose four continuous sections alternate between plangent exhortations for soprano and tape or combative interplay for piano and orchestra. Confrontational in a manner typical of middle-period Nono, its most striking section, ‘The Long March’, brings an ascent from the depths through to the heights of the orchestra in itself electrifying (as was confirmed by a BBC studio reading two decades ago) while anticipating the exploration of sound which preoccupied Nono in the years ahead.

Such exploration is evident in … sofferte onde serene … (1977), a meditative if by no means tranquil piece for piano and tape that unfolds not so much in waves as eddying layers where acoustic and electronic sources fuse as well as exchange their identities to a transformational degree. Jan Michiels is an assured exponent and his reading is the first to use a reconstructed stereo tape that affords a presence and lustre not heard since Pollini’s account four decades ago.

Having prepared the critical edition of this piece, Paulo de Assis (b1969) also undertook an orchestral realisation. With its scoring for spatial forces itself inspired by Nono’s later music, unfolding waves … con luigi nono (2012) is akin to a sonic X ray that opens out the original’s content in new and unexpected ways. It makes a thoughtful end-piece to a disc that, complete with diagrammatic overviews of each work, is a valuable addition to the Nono discography.