Boa noite is a sentimental piano piece that utilizes a song-like melodic structure common in 19th-century salon repertoire. The piece evokes a calm, evening-like atmosphere through gentle harmonic progressions.
Develop a singing tone (cantabile) to bring out the emotive quality of the main theme.
Comparable difficulty and character — good candidates for what to learn next.
Boa noite is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 4.
You should be comfortable at Henle level 3 — meaning you can already play level 2–3 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 Boa noite lasts about 4 minutes.
Boa noite 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 'O sole mio by Eduardo Di Capua, Believe Me, If All those Endearing Young Charms by Irish Folk Music, Belle of the Ball by Leroy Anderson — see the full similar-pieces list on this page.