A highly expressive romantic composition that utilizes a broad, hymn-like melodic style. Its distinctiveness lies in the elegant ornamentation that decorates the recurring primary theme.
The challenge lies in executing the delicate ornamental flourishes with perfect rhythmic alignment within the slow tempo.
Comparable difficulty and character — good candidates for what to learn next.
'O, morning star' is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
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 'O, morning star' lasts about 5 minutes.
'O, morning star' 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 'Break, break, break' by Alfred Humphries Pease, 'Red cloud' by Alfred Humphries Pease, 'La Perichole' by Alfred Humphries Pease — see the full similar-pieces list on this page.