This canon is part of Bach's 'Goldberg' variations-related cycle of canons. It is a masterpiece of compact, logical construction that rewards careful analytical listening.
Maintain absolute rhythmic precision to reflect the Baroque character.
Canon in G major (BWV 1076) is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 5.
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 Canon in G major (BWV 1076) lasts about 1 minute.
Canon in G major (BWV 1076) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.