The solemn introduction shares its opening harmonic progression with the theme, differing only in major/minor mode and tempo. Furthermore, fragments of the theme are skillfully interwoven into its melody. In the variations that follow the theme's presentation, an elaborate structure comes to the fore, emphasizing diverse transformation techniques and, in some variations, alterations to the bar structure and harmony, rather than a mere display of performing virtuosity. This meticulousness distinguishes the work from the variations on popular melodies that Clementi often placed in the final movements of his sonatas during his youth. It is perhaps for this reason that the work is designated not merely as "Variations" but as a "Fantasy with Variations."

Around the same period this fantasy was composed, Pierre-Joseph Zimmermann (1785–1853), then head professor of piano at the Paris Conservatoire, also created a work using the same theme: "Joke on the Folk Song 'Clair de Lune'," Op. 8 (a substantial work, far from a mere joke), which is a type of paraphrase. It is highly interesting to observe similarities in the treatment of the theme.

Dedicated to the wife of Marshal Moreau, who achieved numerous military successes from the Revolutionary period to the Imperial era. She was of Creole descent and was also known as an excellent pianist.