In the reading with a proto-background ^3-^5, I emphasized the static, or radically anti-teleological, character of a hearing that takes hold of that very prominent first interval and never lets go of it. In this post, I try to mitigate that effect by posing a progression from ^3-^5 at the beginning to ^1-^3 at the end -- in other words, an interplay of the upper third with the lower third of the triad.
In one take on this, it is possible to speak of a play of (diatonic) symmetries about ^3-^5; in the other, a line that descends from the opening background third to the lower, closing third pushes the reading very close to a traditional Schenkerian analysis, albeit with a structural alto and an incomplete line.
The upper third is firmly placed in both right and left hand parts at the beginning (see circled notes below). When the topmost part takes the turning eighth notes, it sets them above that upper third (as F#5-A5); then the alto voice sets them below (as A4-C#5, not the strictly symmetrical G#4-B4). The upper third is reinstated for the second phrase but both thirds are present in the cadence. The upper third controls the whole of the C# major section, but the repetition of the cadence at the end of the reprise seems to give the last word to the lower third, and the progression is nicely echoed in the left hand's final quarter notes: C#4-E4- (rep) - A3-C#4.
Another way to look at it is in terms of a harmonic progression supporting voice leading, as in the graphic below.
A foreground representation (below) shows that, once collapsed into the narrowest voice leading patterns, the music hardly moves except to traverse the third-space.
