Glazunov's Op. 101 consists of four substantial preludes and fugues, demonstrating his mastery of contrapuntal writing within a late-Romantic framework. This set is known for its rich harmonies and grand scale.
Challenges students with complex contrapuntal textures and demanding virtuosic sections.
4 Preludes and Fugues (Op.101) is rated Henle level 7 of 9 — late advanced repertoire, roughly ABRSM grade 8 and above. In the RCM system it corresponds to about level 9.
You should be comfortable at Henle level 7 — meaning you can already play level 6–7 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 4 Preludes and Fugues (Op.101) lasts about 6 minutes.
4 Preludes and Fugues (Op.101) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.