Written by the famed Brazilian flautist and composer Patápio Silva, this piece displays a high degree of melodic expressiveness. It stands out for its vocal-like phrasing and melancholic, sighing chromaticism typical of the late Romantic era.
Mastery of rubato and the ability to balance the voicing between the soprano melody and inner harmonic lines are essential.
Comparable difficulty and character — good candidates for what to learn next.
Amor perdido (Op.9) 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 Amor perdido (Op.9) lasts about 4 minutes.
Amor perdido (Op.9) 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 Body and Soul by Johnny Green, Prelude in E minor, No. 4 by Frédéric Chopin, Fantasy in D minor by Wolfgang Amadeus Mozart — see the full similar-pieces list on this page.