Joachim Raff's Op. 171 comprises two songs for mixed choir, reflecting the rich Romantic choral tradition. These pieces are characterized by their lyrical melodies and often intricate harmonic accompaniments.
Careful attention to ensemble balance and the precise execution of dynamic nuances is required.
2 Gesänge für gemischten Chor (Op.171) 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 Gesänge für gemischten Chor (Op.171) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.