Eduardo Souto's Desilusão is a classic example of Portuguese/Brazilian salon music with deep emotional resonance. It is known for its dramatic shift in register and dense chordal textures.
At Henle 4 this is an intermediate piece that expects secure technique and real attention to phrasing. The main demands: rubato that must breathe naturally without losing the pulse; a true singing tone, with the melody floating above the accompaniment; and chord voicing — bringing out one note inside a handful of others.
Beyond that, expect several simultaneous layers, each needing its own dynamic level.
Focus on the projection of the bass line to support the intense emotional character.
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.
Lesser-known works by the same hand, at a comparable level.
Desilusão is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
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 Desilusão lasts about 3 minutes.
Desilusão 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 Coincidências by Eduardo Souto, As quatro estações do ano by Eduardo Souto, Coisinhas... by Eduardo Souto — see the full similar-pieces list on this page.