Of the pieces cited with approval by Poulenc, the fifteen Improvisations were composed at intervals between 1932 and 1959. All are brief: the longest lasts a little more than three minutes. They vary from swift and balletic to tender lyricism, old-fashioned march, "perpetuum mobile", waltz and a poignant musical portrait of the singer Édith Piaf. Poulenc's favoured Intermezzo was the last of three. Numbers one and two were composed in August 1934; the A flat followed in March 1943. The commentators Marina and Victor Ledin describe the work as "the embodiment of the word 'charming'. The music seems simply to roll off the pages, each sound following another in such an honest and natural way, with eloquence and unmistakable Frenchness." The eight nocturnes were composed across nearly a decade (1929–38). Whether or not Poulenc originally conceived them as an integral set, he gave the eighth the title "To serve as Coda for the Cycle" ("Pour servir de Coda au Cycle"). Although they share their generic title with the nocturnes of Field, Chopin and Fauré, Poulenc's do not resemble those of the earlier composers, being "night-scenes and sound-images of public and private events" rather than romantic tone poems.