In the “Nocturnes” for orchestra and women’s chorus, composed between 1897 and 1899, Debussy realised his concept that the musical form should emerge freely from the material. With the tripartite structure, he referenced the symphony, but at the same time distanced himself from it by replacing the motivic-thematic aspects with a variety of nuanced timbres. The movement titles “Nuages” (clouds), “Ftes” (festivals) and “Sirnes” (sirens), deriving from nature and culture, allude to the programme music that was popular at the time. However, Debussy was not interested in tone-painting, but rather in poetic imagination. The arrangement of such an impressionistic masterpiece for two pianos, which Ravel completed in 1909, was a challenge that the young composer mastered most brilliantly. Together with Louis Aubert, he also gave the successful premiere on 24 April 1911 in the Salle Gaveau in Paris. We were able to enlist Debussy specialist Denis Herlin for the first critical edition of the arrangement, with Andreas Groethuysen contributing the fingerings.