Bach's '52 Choralarbeitungen' are settings of Lutheran chorale melodies, showcasing his mastery of contrapuntal writing and harmonic richness. These pieces serve as profound meditations on the liturgical texts they accompany.
Focus on the clarity of each melodic line and the expressive shaping of the chorale melody.
52 Choralarbeitungen is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 7.
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.
52 Choralarbeitungen is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.