This nocturnal work emphasizes harmonic tension and mood-based phrasing rather than virtuosity. It stands out for its deep, somber melodic development in the minor key.
The primary challenge is shaping the melodic phrase with emotional weight while maintaining a steady, unobtrusive accompaniment.
Comparable difficulty and character — good candidates for what to learn next.
Allegro in C minor 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 Allegro in C minor lasts about 4 minutes.
Allegro in C minor 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 Piano Sonata No. 14 'Moonlight', No. 2 by Ludwig van Beethoven, Nocturne in C-sharp minor by Frédéric Chopin, Body and Soul by Johnny Green — see the full similar-pieces list on this page.