Schubert's set of waltzes, Ländler, and ecossaises (Op. 18, D. 145) are delightful miniatures showcasing his gift for melody and rhythmic vitality. These dances capture the spirit of Viennese social music with characteristic charm and harmonic richness.
Mastering the subtle rhythmic nuances and graceful phrasing of these Viennese dances is paramount.
38 Waltzes, Landler and Ecossaises(Op.18) (D.145) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
38 Waltzes, Landler and Ecossaises(Op.18) (D.145) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.