Commissioned by Radio France for L'Itineraire, Valley of Aosta is written for 13 instruments including 2 harps, one tuned a quarter-tone high. Similarly one of the 2 synthesizers is also tuned a quarter-tone up. In addition, there are three sequences of rapid notes which are played by a small computer on the synthesizer. Quarter-tones are deployed by most of the instruments from time to time. The music is often very rapid and fragmented. The figures and their repetitions are atomised in fluid sequences and, at the end of the piece, suggest a kind of spray in which the ideas are swept along. There is a parallel concept in Turner’s Valley of Aosta (1836) – a snowstorm, avalanche and thunderstorm: an explosion of energy and diffracted light, virtually without any figurative reference. Jonathan Harvey