# Is the 2nd movement of Mozart's Piano Sonata nº 7 in C, K.309, a "large rounded binary"?

My analysis of the form of the movement is, currently, that it is a large ternary with written out repeats of the main theme and the subordinate theme complex + return of the main theme together, something like a 'rounded large binary'. A summary of the analysis is below:

• Main theme: cc. 1-17
• Main theme (repeated): cc. 17-33
• Subordinate theme complex: cc. 33-45
• Main theme (returned): c. 45-52
• Subordinate theme complex + main theme returned (repeated): cc. 53-72
• Coda: cc. 73-79

The problem is that the second section of a large ternary is normally an interior theme or at best, a "subordinate theme complex within the framework of the minore" (Analyzing Classical Form, p. 582), which is not the case since we are in the subordinate key. Also, are repeats "allowed" in large ternaries?

I analyzed the main theme as follows, the line and dashes indicate measures and beats, respectively, and the number below them are measure numbers:

And the subordinate theme complex as:

Standard abbreviations for cadences are used, and the remaining abbreviations translate as:

• BId - basic idea
• Cnt - continuation

Were it not for the repetitions, the case here might be of a sonata without development with a truncated recapitulation, I think.

As I'm not all that used to analyzing slow movements I may be missing something basic here, I apologize if that is the case.

The movement is in rounded binary form. A very clear analysis is given on YouTube in the comment section of the linked video.

In summary:

A section (1st period)

• mm. 1–8: theme a, antecedent phrase
• mm. 9–16: theme a1, consequent phrase

A section

• mm. 17–24: theme a2
• mm. 25–32: theme a3

B section

• mm. 33–40: theme b
• mm. 41–44: theme c

A' section

• mm. 45–52: theme a4

B section

• mm. 53–60: theme b1
• mm. 61–64: theme c1

A' section

• mm. 65-72: theme a5

Coda

• mm. 73–79
• I do not particularly like the analysis in the video. It equates what I see as a particular variation process, for a reference to the theme and variations form. As variations, as in written out repeats, are very common outside theme and variations, I don't think that form is particularly relevant here. Commented Apr 30, 2022 at 11:25
• Apart from that, it is interesting to see here the 'large rounded binary' interpretation. Commented Apr 30, 2022 at 11:30
• Also, the analysis does not comment on the fact that the paired 'variations' form a compound period, which I think is a very relevant formal aspect. Commented Apr 30, 2022 at 11:32
• @FelipeMartins I don't understand your comment. There is no reference to "theme and variations"; it is in complete agreement with the idea of a variation process and makes no claim toward anything other than a standard rounded binary. As far as the fact of a period goes, I've alluded to that in my summary, but it doesn't change the fact of the overall rounded binary structure. Commented Apr 30, 2022 at 14:33
• @FelipeMartins Fair enough. When I get a chance, I'll fill out my own analysis and deemphasize the video. Commented Apr 30, 2022 at 15:26

After some thinking, I realized the form may be considered, simply, a small ternary with written-out repeats and with a compound period for an A section. Although it is not a normative situation, I believe it is not explicitly 'forbidden' as is the case of a large ternary with a subordinate theme. Following that, the full analysis will be as below (click the image if it is too small).

What is called the subordinate theme complex in the OP is a modulating B section with a retransition (see Analyzing Classical Form, p. 223, by William Caplin) and the A' section is a compound consequent, which results from the normative shortening of the A section by removing its antecedent phrase.

I am tempted to call the overall form a 'compound small ternary', but I believe the creation of a such a new category, in the context of the theory of formal functions, would be warranted only if there were numerous other examples of the same formal type. Which begs the question: are there?

One should also ask if an 'expanded' small ternary like this one is appropriate for a full-movement form. I also do not know.

• Since the OP specifically asks about rounded binary it seems worth mentioning that Caplin in Classical Form, in the Small Ternary chapter, says: "one of the most vigorous debates in the history of theory concerns whether the simple form under consideration her...consists essentially of two or three parts." He's pointing out rounded binary and small ternary are "essentially the same form." Commented Sep 27, 2022 at 17:11