These two works are like fragments from Nono's late creativity. This beginning more or less with the piano piece with Magnetic tape dedicated to Maurizio Pollini, :sofferte onde serene:, serene waves endured.
A lifelong inhabitant of Venice, Nono on the island Giudecca where he had lived had the timbres the fragments of water,of lapping gentle violent miniature waves always as part of his consciousness.:sofferte onde serene: has this tympani like thuds, soft gentle as accompaniment to the live paino, pre-recorded materials as here this CD of the pianist or performer. This gives a kind of signature, and Nono was fond of dedications in his work(Carlo Scarpa, Andrei Takovski, Edmund Jabes, Pierre Boulez,Emilio Vedova,not to mention lost revolutionaries,activists thinkers,intellectuals) Nono's sensibility inhabits also a very private space as a creator/recluse despite his extroverted political affinities,and this late work certainly reflects a turn inward, as the end of modernity the paradigm lived worked upon, yet a renewal of it.
The antiphonal approach here in these two works is further a way of isolating the tones,as humans are isolated, where a Wall is placed around their existence, the drawn bow, in the highest positions on the violins,col legno at times, with part of the wood of the bow drawn with the hair; pencil-thin harmonics as well, tortured timbre, like fingernails being dragged on the chalkboard, an image that rings with resonance today with the mindless atrocities which continue around the globe.A plucked string, a normally drawn bow becomes, within this context, a means of escape to what the mind already knows. Nono a lifelong Marxist saw the end of the old ways or the process of creating art within the activist paradigm, although he himself never went in the direction as say Cornelius Cardew in England,editing a Marxist newspaper,holding worker meeting,organizing demonstrations.He still envisioned a music with the component of innovation without dilution of its content for the cash box.
Although he did desire to travel to the USA for concerts with much of this late music on this disk, where his Visa was turned down by Washington.
If you can refer to the beautiful as seen through the convoluted maze of the 20th Century,then these works are summoned as the last form of beauty possible,at least within the genre of music Nono had been working. He always detested the freedom of performance through graphic notation and had early diatribic essays against the Cage purposeless purpose. Even here the gifted Gidon Kremer is kept on a short leash, not allowed to travel too far away from the materials given. And he comes to be simply a mimetic form of himself with the pre-recorded materials as the earlier Pollini. No ego or hypocrisy is allowed to reveal itself in the performer's role, merely following a loose but pre-determined plan.If you have ever experienced this music live it is deeply disturbing, unless you merely esacpe to the realm of the aesthetic, then these two works are quite interesting to contemplate. All these late works have this performative freedom, or the representation of it,as the interesting array of silences in the string quartet, "Fragmente,Stille fuer Diotema" where as another reviewer said they come to accrete the tension as the piece progresses. Here as well, although here the silences are not as pronounced,nor as a functional component yet Nono allows the performer to find his/her own way through rests of indeterminate length. The Tuba and Live Electronics work :Post-Praeludium per Donau:(also written within this period after the Danube another water representation) allows the perfomer to choose paths ad libitum, to find their own way. I don't think we can comsider these works as having a constant factor for success, some may still call it "masterpiece", I don't think Nono thought of these works as such, more as fragments, offerings, as a pilgrim bringing a gift to the final destination of their travels.