Jashiin’s piece is an evocative modern work that experiments with non-linear time and texture. Its distinctiveness lies in its experimental approach to atmospheric soundscapes within a classical framework.
Focus on the nuance of touch and pedaling to create the requested atmospheric sound.
Comparable difficulty and character — good candidates for what to learn next.
Canon 'Adagio senza tempo' 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 Canon 'Adagio senza tempo' lasts about 4 minutes.
Canon 'Adagio senza tempo' 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 Canon by Jashiin, Boltzmann Brain by Jashiin, Gymnopédie No. 1 by Erik Satie — see the full similar-pieces list on this page.