This is a complex 20th-century work that explores the intersection of free-form musical architecture and rigorous contrapuntal logic. It is distinctive for its sudden shifts in texture and non-traditional tonal palette.
Focus on the precise rhythmic execution of the disparate textural layers throughout the piece.
Comparable difficulty and character — good candidates for what to learn next.
'Musical composition, an Ineffable Act between Fantasy and Rigour' 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 'Musical composition, an Ineffable Act between Fantasy and Rigour' lasts about 7 minutes.
'Musical composition, an Ineffable Act between Fantasy and Rigour' 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 Cadenza for piano by Liana Alexandra, Allegro veloce e caratteristico by Liana Alexandra, Basso Ostinato, VL 267 by Mikalojus Konstantinas Čiurlionis — see the full similar-pieces list on this page.