Pollini was a virtuoso who composed this work to highlight the technical brilliance of the early piano action. It features constant motion typical of the toccata form, bridging late Classical and early Romantic styles.
At Henle 6 this is an advanced piece that assumes fluent technique and rewards mature interpretation. The main demands: fast passage work that stays light and even at tempo; sweeping arpeggio figures that must stay smooth across positions; and precise articulation — the difference between crisp and blurred is the piece.
Beyond that, expect continuous sixteenth-note figuration that must ripple, not chatter.
Achieving an even, crisp velocity in the perpetual motion passages is the primary requirement.
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.
Esercizio in forma di Toccata op.42 is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 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 Esercizio in forma di Toccata op.42 lasts about 5 minutes.
Esercizio in forma di Toccata op.42 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 Fantaisie-Impromptu in C-sharp minor by Frédéric Chopin, Dizzy Fingers by Zez Confrey, Rondo capriccioso in E major by Felix Mendelssohn — see the full similar-pieces list on this page.