This piece is a delicate miniature from the Brazilian composer's Suite infantil No. 1. It is distinctive for its bittersweet harmonic language that blends traditional lullaby tropes with subtle 20th-century impressionistic coloring.
Focus on maintaining a seamless, singing melody line against the rhythmic accompaniment.
Comparable difficulty and character — good candidates for what to learn next.
Berceuse da Boneca Triste (Op.39) 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 Berceuse da Boneca Triste (Op.39) lasts about 3 minutes.
Berceuse da Boneca Triste (Op.39) 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 Berceuse da Boneca Triste by Oscar Lorenzo Fernández, As estrelas by Oscar Lorenzo Fernández, Berceuse da onda by Oscar Lorenzo Fernández — see the full similar-pieces list on this page.