Bach's 8 Choral Preludes are a collection of masterful organ compositions based on Lutheran hymns. They demonstrate his profound understanding of counterpoint and harmonic richness, often imbuing simple chorale melodies with complex and moving textures.
Developing a clear contrapuntal texture while maintaining a smooth, cantabile line in the melody is a key challenge.
8 Choral Preludes is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 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 8 Choral Preludes lasts about 15 minutes.
8 Choral Preludes is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.