Rudolf Friml, better known for his operettas, wrote this lyrical Berceuse that retains a lush, vocal-like quality. It is distinguished by its rich harmonic colors typical of the era's light music.
The challenge lies in managing the wide-span left hand accompaniment while maintaining a continuous singing line.
Comparable difficulty and character — good candidates for what to learn next.
Berceuse 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 Berceuse lasts about 4 minutes.
Berceuse 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 At Twilight by Rudolf Friml, Berceuse by Rudolf Friml, Boola boo by Rudolf Friml — see the full similar-pieces list on this page.