This piece is a prominent example of mid-20th-century French piano writing that emphasizes atmosphere and modal exploration. It is known for its austere beauty and non-traditional harmonic progressions.
Mastering the subtle shifts in harmonic color requires precise control of touch and weight.
Comparable difficulty and character — good candidates for what to learn next.
Ballade en mode phrygien is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 9.
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.
A typical performance of Ballade en mode phrygien lasts about 5 minutes.
Ballade en mode phrygien 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 Ballade en mode phrygien, JA 9 by Jehan Alain, 12 Variationen uber en eigenes thema by Alban Berg, 12 Variationen über ein eigenes Thema by Alban Berg — see the full similar-pieces list on this page.