Felipe Brandes' '2 Nocturnes for Harmonium' are likely written with the specific timbral qualities of the harmonium in mind, focusing on sustained tones and expressive phrasing.
Explore the unique coloristic possibilities of the harmonium and maintain a steady, resonant sound.
2 Nocturnes for Harmonium (Op.55) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7.
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.
2 Nocturnes for Harmonium (Op.55) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.