These are lesser-known but well-crafted Romantic pieces by Widor, likely featuring the virtuosic flair and clarity of texture characteristic of his organ music applied to the piano. They offer a rewarding challenge for advanced pianists.
Focus on clean articulation and precise execution of fast passagework.
3 Nouvelles pièces is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 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.
A typical performance of 3 Nouvelles pièces lasts about 7 minutes.
3 Nouvelles pièces is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.