I Capture the Castle guests describe each other in terms of famous artists. Topaz is called a work by William Blake, Rose is said to resemble Emma, Lady Hamilton, the muse of the painter George Romney, Simon says that Cassandra is like "Girl with a Mousetrap," a painting by Joshua Reynolds, and Mrs Fox-Cotton is said to be a work by Salvador Dalí "with snakes coming out of her ears". Simon introduces Cassandra to the works of Claude Debussy: "Clair de lune", "La cathédrale engloutie", "La terrasse des audiences du clair de lune". She also listens to J. S. Bach's "Sheep May Safely Graze"
Au clair de la lune clair de la lune" as the basis of his song "Pierrot" ("Pantomime", L. 31) from "Quatre Chansons de Jeunesse". Erik Satie quoted this song in the section "Le flirt" (No. 19) of his 1914 piano collection "Sports et divertissements". In 1926, Samuel Barber rewrote "H-35: Au Claire de la Lune: A Modern Setting of an old folk tune" while studying at the Curtis Institute of Music. In 1928, Marc Blitzstein orchestrated "Variations sur 'Au Claire du la Lune'." In 1964, French pop singer France Gall recorded a version of this song, with altered lyrics to make it a love song.