Berio’s compositions for solo piano (two or four hands) make up a relatively small part of an output rich in large-scale vocal and orchestral works that push perceptively at the boundaries of historical convention where form and style are concerned. Both of his major works – Sequenza IV and the Sonata – probe the nature of an instrument whose lack of the sustain possible with a violin or an oboe frees the modernist-minded composer from quasi-vocal lyricism while challenging him to build effective designs from the contrasts between single notes, chords and flourishes short or long, the latter often testing the performer to the limit with rapid note repetitions.

At c23 minutes, the Sonata (2001) is more than twice the length of Sequenza IV (1965‑66) and is correspondingly more enigmatic in its materials and processes. Is the emphasis on the single note B flat (B in German, as in BACH, where H signals B natural) a wry signature, acknowledging both Berio himself and the piece’s dedicatee, his Harvard colleague Reinhold Brinkmann? Whether it is or not, Berio makes no attempt to link the sonata to the kind of Schubertian or Brahmsian precedents acknowledged in other examples of his later works. If anything, it is more like an expansive reconsideration of the masterly Sequenza IV, the outstanding item on this new CD, with its laser-bright acoustic allowing full weight to the crucial role of the sostenuto pedal.

Matteo Bevilacqua steals a march on his precursor, Francesco Tristano Schlimé, who made the first recording of the Sonata (Sisyphe, 7/07) but did not include in his ‘complete’ collection the two brief but entirely characteristic items for piano four hands from 1991, Canzonetta and Touch. Among the other miniatures, the early Five Variations still impresses with its turbulent departures from the more gentle, poetic responses to Webern’s later style favoured by one of Berio’s teachers, Luigi Dallapiccola, while for all its brevity, Rounds is a hard-hitting pendant to Sequenza IV, compressing its gestures into an even pithier formal network than the Sequenza itself displays. It is very good to be reminded of the special qualities of this music at a time, two years before Berio’s birth centenary, when one hopes for new recordings of some of those larger-scale orchestral and vocal – especially operatic – compositions.