François Delor provides a stylistic exploration of the famous French folk song through a series of varied character sketches. Each section presents a different harmonic and rhythmic approach to the familiar, simple melody.
Students must maintain clear melodic lines through shifting harmonic contexts in each variation.
Comparable difficulty and character — good candidates for what to learn next.
"Au clair de la lune..." dans tous ses états is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 4.
You should be comfortable at Henle level 3 — meaning you can already play level 2–3 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of "Au clair de la lune..." dans tous ses états lasts about 3 minutes.
"Au clair de la lune..." dans tous ses états is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Albumblatt by Johannes Brahms, (Four Note) Pavan by Richard Farrant, Berceuse, H.8d by Frank Bridge — see the full similar-pieces list on this page.