...che notturno canta insonne

Evolving harmonic structures were created using IRCAM Open Music, based on continuous expansions of the harmonic series. Non-integer partials were introduced whenever the intervals in the resulting spectrum became too wide, allowing continued expansion. These were rounded to quarter-tone resolution, and the pitches scored by means of tuning nearly half the orchestra down a quarter-tone. Rapid runs in the strings were achieved by interpolation between two subsets of the same spectrum, with hocketting patterns used to achieve the quartertones. Other aspects of the piece were freely composed, drawing on the harmonic process provided by Open Music in order to give a sense of continuous expansion.

The research findings showed that a continuous background harmonic process can provide a plausible large-scale harmonic template, in the absence of tonality, for otherwise free orchestral composition. They also showed that de-tuning nearly half the orchestra is a very effective way to achieve a full range of quartertones.

If this is a kind of nocturne, it is one that evokes a serene yet intense wakefulness in the dark, rather than hushed rustlings and murmurings. In the poem by Pascoli from which the title is taken, the ocean sings by night in order not to sleep, and while this piece does not directly evoke the sea, there is perhaps an oceanic aspect to some of the music given to the horns (the instrument used by Poseidon’s son Triton to calm the sea). Metal percussion and harp coalesce into cadences – echoing the arpeggiated accompaniment of the nineteenth-century nocturne – and part of the orchestra is tuned a quarter-tone lower to allow more subtle harmonic movements and inflexions.