Julian Fontana was a close associate of Chopin, and his music reflects the same keyboard idioms of the period. This work is characterized by wide-spanning left-hand accompaniment and highly expressive melodic lines.
At Henle 5 this is a late-intermediate piece — technically substantial, with musical demands to match. The main demands: a true singing tone, with the melody floating above the accompaniment; rubato that must breathe naturally without losing the pulse; and big chords that need weight without harshness.
Mastering the wide-span left hand without sacrificing the flow of the melody is essential.
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.
Elegie (Op.7) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
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 Elegie (Op.7) lasts about 5 minutes.
Elegie (Op.7) 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 Asturias (Leyenda) by Isaac Albéniz, Dumka by Antonín Dvořák, Elegy No.1 by Franz Liszt — see the full similar-pieces list on this page.