BWV 1073 is a short, perpetual canon by Bach that exemplifies his mastery of voice-leading within a minimal time frame. It is distinctive for its dense, economical use of melodic material.
The technical hurdle lies in executing the rapid sixteenth-note patterns with perfect finger independence.
Canon in A minor (BWV 1073) 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 Canon in A minor (BWV 1073) lasts about 1 minute.
Canon in A minor (BWV 1073) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.