Léon Delafosse, a pupil of Massenet, brings a French refinement to this waltz. It is distinguished by its expressive, fluid melodic writing and nuanced harmonic shifts.
Developing a flexible, singing tone that can navigate the shifting harmonic textures is key.
Comparable difficulty and character — good candidates for what to learn next.
Au bal (Op.90) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 6.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 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.90) lasts about 4 minutes.
Au bal (Op.90) 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 16 Waltzes by Johannes Brahms, Albumblatt in Walzerform by Franz Liszt, Ballade by Cécile Chaminade — see the full similar-pieces list on this page.