This chorale prelude by Bach is a keyboard arrangement of a hymn, showcasing Bach's mastery of contrapuntal writing. It is characterized by its joyful energy and the interplay between the melodic lines derived from the chorale.
Developing clear finger independence to articulate the independent melodic lines is crucial.
Auf, auf! die rechte Zeit ist hier (BWV 440) 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 Auf, auf! die rechte Zeit ist hier (BWV 440) lasts about 1.5 minutes.
Auf, auf! die rechte Zeit ist hier (BWV 440) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.