Cramer's Etudes are foundational works in piano pedagogy, celebrated for their clarity and focus on developing legato, finger strength, and melodic line. They are essential for building a solid technical base.
Concentrate on developing a consistent, singing tone and achieving evenness in scale and arpeggio passages.
12 Études mélodiques (Op.107) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
12 Études mélodiques (Op.107) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.