Mozart's 'Andante and Variations' K.501, though often listed as C major, has a counterpart in G major with a similar K. number (though K.501 is definitively C major; this might refer to a different K. number or an arrangement). Assuming a similar character, it would feature a graceful theme developed with Mozart's characteristic wit and clarity. Its distinction lies in its charming melodic invention and elegant structural balance.
Focus on clarity of articulation, precise rhythmic execution, and graceful phrasing in each variation.
Andante and Variations in G major (K.501) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 Andante and Variations in G major (K.501) lasts about 6 minutes.
Andante and Variations in G major (K.501) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.