Considered unanimously as one of the peaks of post-war opera, Prometeo was the acme of Nono's research, begun towards the end of the 1960s, about the sense of making music and the very aim of art, in conjunction with the reflective withdrawal of it's expressive instruments and musical contents after his combative years of "commitment". After a four-year elaboration work, in close cooperation with Massimo Cacciari, the opera debuted on 25th September 1984, under the baton of Claudio Abbado, in San Lorenzo's deconsecrated church in Venice, where Renzo Piano had created an enormous wooden structure similar to a ship, or the soundbox of a huge lute, to accommodate the audience. Around it, at different distances from the floor and on the structure itself, the musicians moved, with very few visual effects created on purpose by Emilio Vedova. After a deep revision, the opera was staged in a definitive version exactly a year later in Milan. Prometeo is a work that refuses to relate, to represent, to compromise the listening with scenography precisely because it was born with a will to explore and stimulate a deeper ability of listening, that was supposed to be, actually, an invitation not to accept any preconceived reality. The libretto itself does not aim simply to narrate the story of Prometheus, but to evoke it through a dense net of quotations in three languages within autonomous segments that refer back to ancient theatre and quantified, roaming perception (Prologue, interludes, stasima, islands). On this basis, Nono set up a score of unprecedented, off-putting, movable and encircling sounds, often bordering on silence, manipulated by live electronics, so as to make the space tangible by eliminating the direct and conventional relationship with the drama, crushed between reciting voices, choir and solo singers, whose texts are never pronounced or sung in a conventional way. It is therefore a drama of sounds, neither of actors nor of characters: the "tragedy of listening" should be understood as the ability to seize what happens in a unique, unrepeatable moment, which exhorts us each time to overcome our limited knowledge without taking anything for granted.