Desiré Magnus was a prolific composer of salon piano music, and this waltz exemplifies the light, social music of the 19th century. It is characterized by its infectious rhythmic lilt and standard dance form.
Students must master the light, 'oom-pah-pah' feel of the left hand while maintaining melodic flexibility.
Comparable difficulty and character — good candidates for what to learn next.
Au bal (Op.201) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 bal (Op.201) lasts about 4 minutes.
Au bal (Op.201) 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 The Entertainer by Scott Joplin, 12 Variations on "Ah vous dirais-je, Maman" by Wolfgang Amadeus Mozart, Piano Sonata No. 11 in A major by Wolfgang Amadeus Mozart — see the full similar-pieces list on this page.