Densmore’s work is a quintessential example of mid-level salon repertoire from the early 20th century. It relies on a classic waltz structure to evoke a sense of graceful, light-hearted movement.
Ensure the waltz-rhythm remains light and does not become overly heavy or percussive.
Comparable difficulty and character — good candidates for what to learn next.
Butterfly is rated Henle level 2 of 9 — beginner repertoire, roughly ABRSM grades 2–3. In the RCM system it corresponds to about level 4.
You should be comfortable at Henle level 2 — meaning you can already play level 1–2 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 Butterfly lasts about 2 minutes.
Butterfly 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 Bedtime, TH 70 by Pyotr Tchaikovsky, Au matin by Paul Wachs, Barcarolle by Samuil Maykapar — see the full similar-pieces list on this page.