Nuages gris [SEP] instrumentation
Nuages gris
Nuages gris (; French, lit. "Grey Clouds"), S.199 or Trübe Wolken, is a work for piano solo composed by Franz Liszt on August 24, 1881. It is one of Liszt's most haunting and at the same time one of his most experimental works, representing, according to Allen Forte, "a high point in the experimental idiom with respect to expressive compositional procedure."'
Departing from his earlier virtuoso style, Liszt in his later years made several radical, compositional experiments
a clear affinity with the somewhat later expressionism of the Viennese composers Mahler and Schoenberg... ["Nuages gris"] is a musical bellwether that indicated what was happening and what would happen in European music: sound, with the assistance of symmetry, would take over, harmony would be absorbed into color and lose its cadential function."
Claude Debussy probably had "Nuages gris" in mind when he composed his own "Nuages". 
Mauricio Kagel used "Nuages gris" in his "Unguis incarnatus est" (