This organ prelude and fugue by J.S. Bach is a virtuosic exploration of Psalm 130, characterized by its intricate contrapuntal writing and dramatic intensity. The fugue subject is a powerful descent, reflecting the 'depth' of the psalm.
Mastering the contrapuntal independence of voices and executing rapid arpeggiated figures are key challenges.
Aus der Tiefe rufe ich (BWV 745) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
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 Aus der Tiefe rufe ich (BWV 745) lasts about 4 minutes.
Aus der Tiefe rufe ich (BWV 745) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.