This is a lively and characteristic early classical sonata-allegro movement by Mozart, showcasing clear thematic development and balanced phrasing. Its charm lies in its straightforward melodic lines and energetic drive.
Focus on clean articulation and evenness in the rapid passagework.
Allegro in C major is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 3.
You should be comfortable at Henle level 3 — meaning you can already play level 2–3 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 major lasts about 3 minutes.
Allegro in C major is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.