The piece is based on the phenomenon of clair-obscur, a term derived from painting. Rembrandt’s The Conspiracy of Claudius Civilis served as the source of inspiration for this composition. The sung notes and alternative fingerings represent the effect of obscur, like a shadow of the concrete played notes, which represent the clair.

The piece may be performed on any recorder ranging from voice flute to alto recorder, depending on the singing range of the player. However, all singing must be performed on pitch (not a different octave as written).