This year Wenatchee The Hatchet has finally gotten around to some musical analysis that, in some ideal alternate universe, could have been started a few years ago. For instance, we finally got around to discussing Sor's Op. 29, etude 10 as an example of sonata allegro form recently.
But here's a proposal, there's actually another sonata form lurking within the Op. 29 etudes, No. 5 in C major. But this one's a trickier sonata form because it has so many internal repetitions of themes within the exposition Sor dispenses with what would have been a usual structurally mandated repeat. Instead he jumps from his exposition straight into a development without any formal repeat of the sort we saw in the brilliant little Op. 29, 10 study.
If you peruse the score for this C major etude you'll see, too, that the development section starts with Theme 1 and Theme 2's opening gestures presented as subject and countersubject in a contrapuntal texture. Sor repeated his Theme 1 in a higher register with a countersubject within the exposition so it's set-up that this is going to be a sonata that plays with contrapuntal textures. The rising scalar motif in theme 1 still shows up in theme 2 as an accompaniment gesture. It might be worth noting that Sor transcribed and arranged arias and at least one fugue by Haydn and so he'd have been familiar, it seems, with Haydn's innovation of using an accompaniment idea for a first group as the foundational idea for a second group. But if Haydn took to that in string quartets it could be proposed that here Sor subordinates the core gesture of theme 1 into being an accompaniment figure for Theme 2, Group 1.
Group 2, bracketed off with a note in the jpeg below, shows that as is common in sonata forms written by guitarists in the early 19th century, the second key region generally has more than one theme. Group 2 repeats and if you factor in the chromatic adjustments it is still, basically, a greatly augmented iteration of the rising scalar motif from the first theme.
With so many recurring variations of that riff it's actually no wonder Sor doesn't bother to recapitulate it when Theme 1 was the opening riff in the development section. What Sor does, instead of recapitulating theme 1 as we would "expect" in a sonata form, is make the contour of Theme 1 a rising bass line over which Theme 2, Group 1 and 2, is recapitulated in the tonic key. Think of it as a hybrid recapitulation in which evocations of Theme 1 and Theme 2 happen at the same time.
For those who have read Charles Rosen's book on sonata forms he pointed out that there's no set rule that a theme that has appeared in an exposition has to appear in a recapitulation. The guitarist composers of the early 19th century are particularly good case studies for Rosen's observation. You could have a theme 1 in Diabelli's F major guitar sonata that never appears after the exposition and development are complete. Something similar happens in Molitor's Op. 7 guitar sonata, which we might be able to discuss some time later. While in Sor's Op. 29, 10 etude he brings back both themes where we would expect this is something Sor doesn't always do. In the Grand Sonata Op. 22, for instance, theme 2 is never recapitulated while in Op. 25 the themes are roughly brought back in reverse order. Here in Op. 29, 5 what we see is that the thematic idea of Theme 1 is recapitulated simultaneous to the return of Theme 2 in its groups 1 and 2.
So, in summing up Rosen's observations, sonata forms from the Classic period were more flexible than a "textbook" definition might often lead us to believe. It may be that part of why Sor's deployment of sonata form may not always have accounted for Op. 29 etudes 5 and 10 is that if musicologists aren't flexible enough in how they define exposition and recapitulation in formal terms they may not spot that Sor used sonata forms, arguably, in at least two more cases than were recognized in Stanley Yates' overview of Sor's use of sonata form. Yates' overview is definitely helpful and handy, but the discussions of the Op. 29 etudes that employ sonata form are meant as a supplement so that guitarists can have a fuller appreciation of the sonata forms that show up in Sor's work that may be overlooked because they weren't explicitly labeled as sonata forms and as stand-alone works.
Now, with all that out of the way, it's one thing to tell a reader about these things, and another thing to show them. You'll want to collapse the menus on the side here so that the score may be a little easier to read. The visual analysis/break-down of how and why I think Op. 29, 5 is a sonata form can be perused after the break.