Par BERIO LUCIANO. From Berio's program notes: 'In one episode, namely Il Campo (The Field), from my azione musicale Cronaca del Luogo, there is a virtual love duet. Two voices and several instruments 'fall in love' and follow one another in a constantly renewing relationship. As we all know, in true polyphony each voice contributes to the whole yet retains its own identity, if not complete autono…