Jules Herman’s interpretation of Donizetti themes utilizes the waltz form to elevate operatic motifs into a ballroom-style arrangement. Its distinction lies in the graceful integration of vocal lines within a dance structure.
The primary challenge is to sustain the waltz-rhythm while ensuring the melody sounds operatic and flexible.
Comparable difficulty and character — good candidates for what to learn next.
'L'elisire d'amore' de Donizetti (Op.35) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
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 'L'elisire d'amore' de Donizetti (Op.35) lasts about 6 minutes.
'L'elisire d'amore' de Donizetti (Op.35) 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 'Don Juan' de Mozart by Jules Herman, 'La straniera' de Bellini by Jules Herman, Waltz No. 2 by Dmitri Shostakovich — see the full similar-pieces list on this page.