Another Protuberant 3 in Some Mozart

In January posts on this blog from two and three years ago, I recognized two late eighteenth-century sonata movements in which the recapitulation of the second theme was altered to give scale degree 3 more salience that it had during its exposition.

Here's another example, from very well-known music of Mozart: the first movement of his piano sonata in C major, K. 545. These examples show the end of the second theme in the exposition and recapitulation, respectively. The descending-fifth transposition in the recapitulation avails more room for the treble melody to stretch out in the highest register, of which Mozart takes advantage in m. 65, which is an octave higher than what one would expect given its correspondence with m. 20. It so happens that the highest note during this stretch is E6, which is scale degree 3 in C major. Likewise, Mozart stretches out in m. 69 from what would be down a fifth from m. 24, up via a new scalar arch to the high E6 (which is connected to the beam in red, and followed by another scale degree 2 beamed in red, albeit back down in the treble-clef staff).

I will leave it there. If one wonders how this might intersect with a Schenkerian reading of this entire movement (of which my reading is neither necessarily of the entire movement, nor entirely Schenkerian), I recommend consulting John Synder's intriguing approach to this movement (cited here) at some point.