Part of the Trois études de concert, this work features sweeping arpeggios that span the entire keyboard to create a shimmering, ethereal effect. It is a masterclass in tone production and managing complex melodic voicing within constant motion.
Students must develop a supple wrist to achieve the flowing, undulating arpeggios without ever losing the singing melody.
Comparable difficulty and character — good candidates for what to learn next.
Un sospiro (S. 144) 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.
A typical performance of Un sospiro (S. 144) lasts about 6 minutes.
Un sospiro (S. 144) 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 Liebestraum No. 3 in A-flat major by Franz Liszt, Berceuse by Franz Liszt, Aus Lohengrin by Franz Liszt — see the full similar-pieces list on this page.