This piece is an variant cataloging of the salon-style work by the composer likely known as Glycerio Maciel. It displays the typical sentimental qualities found in turn-of-the-century Brazilian piano literature.
At Henle 4 this is an intermediate piece that expects secure technique and real attention to phrasing. The main demands: a true singing tone, with the melody floating above the accompaniment; rubato that must breathe naturally without losing the pulse; and chord voicing — bringing out one note inside a handful of others.
The main challenge is balancing the lyrical melody against a delicate accompaniment without losing the pulse.
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.
Dr. Diniz P. Passos is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 4.
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 Dr. Diniz P. Passos lasts about 3 minutes.
Dr. Diniz P. Passos 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, Berceuse by Georges Bizet, Dream Children by Edward Elgar — see the full similar-pieces list on this page.