This piece uses typical 19th-century harmonic language to convey a sense of grief. It is a functional and modest work intended for private performance.
At Henle 4 this is an intermediate piece that expects secure technique and real attention to phrasing. The main demands: a true singing tone, with the melody floating above the accompaniment; careful pedaling — clarity depends on the foot as much as the fingers; and a left hand with real melodic or rhythmic responsibility of its own.
Focus on the independence of the left-hand accompanying patterns against the long-breathed melody.
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.
Elegy (Op.70) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 Elegy (Op.70) lasts about 3 minutes.
Elegy (Op.70) 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 Elegie by Bart Verhallen, Nocturne in C-sharp minor by Frédéric Chopin, Pavane pour une infante défunte by Maurice Ravel — see the full similar-pieces list on this page.