Bach's '389 Choralgesänge' are further examples of his skillful harmonizations of German chorales, essential for grasping Baroque sacred music. They offer profound explorations of harmony and voice leading within a devotional context.
Pay close attention to the intervallic relationships between voices and the resulting harmonic richness.
389 Choralgesänge is rated Henle level 2 of 9 — beginner repertoire, roughly ABRSM grades 2–3. In the RCM system it corresponds to about level 3.
You should be comfortable at Henle level 2 — meaning you can already play level 1–2 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
389 Choralgesänge is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.