Almost all the studies of Op 335 feature polyphony in 2 or more voices, and often, as here, 3 and 4 voices. But with 4 voices Czerny tends, as here, to avoid counterpoint; the voices congeal into chordal writing, all moving in the same note values and at the same time (see also #23).
Bringing out voicings in 4-part chords is indeed very difficult on the piano; Bach requires it in most of his keyboard fugues. But Bach doesn’t linger in such chordal writing; Czerny usually persists to the end after a few measures of counterpoint, and while such writing is good training I don’t think it results in the most interesting or attractive music.
To me the most interesting and attractive music of #4 is the contrapuntal material: the brief duet of mm 17-20, and especially the chord progressions of mm 1-8 and 9-16. Czerny’s repeated melodic patterns, with wide intervals in the lower register and close intervals in the top, create the sound of 2- and 3-voice counterpoint, just as Bach’s do. With that in mind, I’ve re-imagined #4 as a roccoco “praeludium” in AABA, with the A section shaped from Czerny’s opening broken chord figures, and the contrasting B section an extension of Czerny’s little duet (mm 17-20). And it’s no longer a study in legato.
Op 335 #4, Single Version: flowing broken chords in “Praeludium” style, 8 sets of 8-count phrases.
This is a performance of my shortcut arrangement of #4, for which I supply a score. I slowed Czerny’s tempo to the half @70, which is about the pace of a typical ballet class 4/4 adagio, but I don’t hear my arrangement as an adagio. I hear it as temps lie, or maybe fondus, or slow tendus. In any case, I feel that Czerny’s common-time material now has, in my arrangement, a cut time rhythm. The means you have to decide on a 2-bar or a 4-bar preparation depending on your tempo and the rhythm you want to project.