François-Joseph Naderman's '7 Sonates Progressives' are pedagogical works exhibiting Classical clarity and melodic grace, suitable for intermediate pianists.
Emphasizes legato phrasing and clean execution of scalar passages.
7 Sonates Progressives is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 4.
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.
A typical performance of 7 Sonates Progressives lasts about 4 minutes.
7 Sonates Progressives is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.