A virtuoso showpiece by one of the 19th century's premier pianists, intended for the concert hall. It is distinctive for its massive scale and technical demands typical of the Thalberg style.
At Henle 7 this is a late-advanced work — the technical demands are serious and sustained. The main demands: fast passage work that stays light and even at tempo; sweeping arpeggio figures that must stay smooth across positions; and octave passages that demand a relaxed wrist to avoid tension.
Beyond that, expect big chords that need weight without harshness.
The challenge is maintaining massive, wide-spanning chordal textures while keeping a brilliant sound.
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.
Divertissement (Op.18) 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 10.
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.
Divertissement (Op.18) 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 Andante final de 'Lucia di Lammermoor' by Sigismond Thalberg, Ballade Célèbre by Sigismond Thalberg, Divertissement sur un thème de 'The Gypsy's Warning' by Sigismond Thalberg — see the full similar-pieces list on this page.