A monumental work from Frederic Rzewski's set of ballades, this piece utilizes the folk song 'It Makes a Long Time Man Feel Bad' as a basis for complex virtuosic variations. It is a hallmark of late 20th-century piano repertoire.
The technical difficulty stems from the extreme independence of hands and the rapid, complex rhythmic shifts throughout the variations.
Comparable difficulty and character — good candidates for what to learn next.
Ballade No. 5 (It Makes a Long Time Man Feel Bad) is rated Henle level 8 of 9 — concert repertoire, roughly diploma level. In the RCM system it corresponds to about level 10.
You should be comfortable at Henle level 8 — meaning you can already play level 7–8 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 No. 5 (It Makes a Long Time Man Feel Bad) lasts about 12 minutes.
Ballade No. 5 (It Makes a Long Time Man Feel Bad) 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 No.6 by Frederic Rzewski, Ballade No.5 by Frederic Rzewski, Cadenza con o senza Beethoven by Frederic Rzewski — see the full similar-pieces list on this page.