The Diabelli Variations, Op. 120, represent the pinnacle of Beethoven's late-period piano writing, transforming a trivial waltz theme into a complex cycle of musical exploration. It is arguably the greatest set of variations ever composed for the instrument.
At Henle 9 this is among the most demanding works in the piano literature. The main demands: independent voices that must each sing on their own line; big chords that need weight without harshness; and wide stretches that reward larger hands and clever redistribution.
Beyond that, expect polyrhythms that have to lock together without sounding mechanical, and sharp dynamic and character contrasts held together in one arc.
At roughly 55 minutes, stamina and memory become part of the challenge — plan practice in sections.
The work requires an immense range of technical skills, including advanced polyphonic control and a profound grasp of architectural pacing.
Comparable difficulty and character — good candidates for what to learn next.
A level or two down with the same spirit — ideal if this piece is still out of reach.
Lesser-known works by the same hand, at a comparable level.
Diabelli Variations Op.120 is rated Henle level 9 of 9 — virtuoso repertoire, roughly concert / virtuoso level. In the RCM system it corresponds to about level 10.
You should be comfortable at Henle level 9 — meaning you can already play level 8–9 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 Diabelli Variations Op.120 lasts about 55 minutes.
Diabelli Variations Op.120 is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Piano Sonata No. 23 'Appassionata' by Ludwig van Beethoven, Piano Sonata No. 21 'Waldstein' by Ludwig van Beethoven, Piano Sonata No. 17 'Tempest', No. 2 by Ludwig van Beethoven — see the full similar-pieces list on this page.