Richard Eilenberg's 'Blau Veilchen' is a classic salon-era waltz featuring graceful phrasing and standard romantic harmonic progressions. Its charm lies in its refined, conversational melodic structure.
The challenge lies in shaping the phrase endings with appropriate rubato.
Comparable difficulty and character — good candidates for what to learn next.
Blau Veilchen (Op.22) 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 Blau Veilchen (Op.22) lasts about 4 minutes.
Blau Veilchen (Op.22) 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 Andante by Wolfgang Amadeus Mozart, Berceuse by Léon Boëllmann, Berceuse by A. Simon — see the full similar-pieces list on this page.