Ernesto Nazareth's '9 de maio' is a charming Brazilian waltz, showcasing his signature style of blending classical influences with native Brazilian musical elements. It features a sweet, lyrical melody and a gracefully flowing accompaniment.
Requires a delicate touch and nuanced interpretation of the waltz rhythm.
9 de maio is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
9 de maio is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.