This work is a vigorous, short character piece that demands rapid finger work and sudden dynamic changes. It leans toward the etude genre in its pursuit of technical facility.
At Henle 5 this is a late-intermediate piece — technically substantial, with musical demands to match. The main demands: fast passage work that stays light and even at tempo; sharp dynamic and character contrasts held together in one arc; and precise articulation — the difference between crisp and blurred is the piece.
Stamina and precise rhythm in the fast-moving passages are essential for this piece.
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.
Where this piece's skills lead: slightly harder works making similar technical demands.
Délire is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 6.
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 Délire lasts about 3 minutes.
Délire 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 Rhapsody in G minor, No. 2 by Johannes Brahms, El Entrerriano by Rosendo Mendizábal, Allegro in D minor by George Frideric Handel — see the full similar-pieces list on this page.