Mozart's "Bastien und Bastienne" is a charming Singspiel, a German-language opera, with many memorable and melodically rich arias and ensembles. Its enduring appeal comes from Mozart's characteristic grace, wit, and lyrical warmth, making it a cornerstone of the early Classical repertoire.
The primary challenge lies in mastering the effortless grace and clarity required for Mozart's melodic lines and ensemble passages.
Bastien und Bastienne is rated Henle level 7 of 9 — late advanced repertoire, roughly ABRSM grade 8 and above. In the RCM system it corresponds to about level 9.
You should be comfortable at Henle level 7 — meaning you can already play level 6–7 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 Bastien und Bastienne lasts about 15 minutes.
Bastien und Bastienne is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.