This is a designation for the first of Schubert's two settings of Mayrhofer's poem 'An Rosa'. It is a tender and lyrical song characterized by its simple, heartfelt melody and warm accompaniment.
Cultivate a natural, singing tone and ensure expressive phrasing to convey the song's gentle sentiment.
An Rosa I (D.315) is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 6.
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 An Rosa I (D.315) lasts about 3 minutes.
An Rosa I (D.315) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.