In mm. 6-7 I earlier analyzed the partial augmented-sixth chord as resolving to a cadential 6/4. But my impression of that chord is not cadential; rather, it constitutes a very strong arrival. Hence, my coining of the term "arrival 6/4" in my book. Other examples may be found in the slow movement of the Hammerklavier (m. 14), as well as the coda to the first movement of opus 101 (m. 90). Notice the rhetorical effect of resolution as well as arrival is more telling at the moment the 6/4 occurs than it is at the actual cadence. Indeed, when I hear the lyrical "y" theme above the ongoing dominant pedal, I do not hear it as unstable, as with the dominant pedal points underlying the second themes of the piano sonatas opus 2, nº1; opus 13; or opus 31, nº2; but rather as remarkably stable -- both presentational and as though the presentation were on a pedestal. Now why should that be? Partly, I think, because of the context of this pedal, which resolves the implied instability of our partial augmented-sixth as well as enunciating the first periodically stable thematic statement. Not only does poignant lowered-6 resolve to 5 in the bass, but crucially the questioning lowered-3 is pulled up to raised-3 in the upper voice. The positive, Picardy-third effect offers its resolutional stability through the following measures. And the glowing consonance of a major 6/4 chord, which was once recognized (by Helmholtz) as acoustically more consonant than the root position major triad, offers perceptual affordance to this interpretation.
I have just given several reasons for a slight reinterpretation of a particular chord, and now I should like to explain how that reinterpretation might be understood semiotically. In terms of markedness, the opposition between minor and major (exemplified in the opposition between mm. 5-6 on the one hand, and mm. 1-4 and 7 on the other) can be quite powerful. In m. 5 it clouds an otherwise positive emotional state with uncertainty that is potentially poignant or even a forewarning of the tragic. In m. 7, its suspended uncertainty is resolved rather gloriously into the arrival 6/4, thus encapsulating the potentially negative within the larger embrace of the positive.
In stylistic terms, minor is marked within major, and thus m. 5 marks the first expressive crux of a movement that begins with a rather general positive energy (topically, a mix of the heroic and hunt-based pastoral, but beginning with such helter-skelter energy as to potentially be setting up a comic reversal). The marked term of an opposition correlates with a narrower realm of meaning (here, the mutated third scale degree disrupts with a strong stylistic correlation, interpretable here as a hint of the poignant, or potentially tragic). But when major in turn reverses (and resolves) minor, as in m. 7, it draws on the marked status of the Picardy third within the realm of minor. Thus, m. 7 may be heard as the second expressive crux of the movement, and its almost premature, positive resolution of the brief moment of poignant uncertainty also puts its stamp on the expressive genre of the movement as a whole. We can be fairly certain that this movement will have a non-tragic outcome (though the issue of F-natural and Bb will have its own consequences thematically).