Scherzo is in Rounded Binary form. The formal scheme is:
[ A (1-16) ] [: B (17-44) A’ (45-66) :]
The A Section starts with an 8 bar melody which is not in tight-knit form, but it is more like a presentation phrase of a sentence. The remaining part of A is the repetition of melody with small variations. It ends with PAC in home key.
The B section uses a material which is fragmented from A section. It is looser in terms of form and contains secondaries. It starts in A flat major and has a secondary to D flat major. Bars 17-20 are a model and it is repeated as a sequence in E flat major and f minor. The rest of the B section occurs as it stands on the dominant of f minor. This section has no contrasting role against A section and is more like a bridge between A and A’. It doesn’t use any new material but fragmentation.
The A’ section is same with A section in terms of musical material. The only difference is that melody first comes in bass line and the upper line contains scale like passage-work. The repetition is the vice-versa; melody in soprano and the passage-work in bass line. These scale like passage works are in the role accompaniment. A’ section ends with a short, closing like codetta.
Although the formal scheme of Rounded-Binary is same with Ternary Form, there is a major difference in terms of the character of music. This difference is always in B sections. In Rounded-Binary, B sections are more like bridge and its contrasting role is lesser. It usually uses motivic and fragmented materials instead of established themes. On the other hand, in Ternary form, B sections are completely in contrasting role as they present contrasting musical ideas and characters against A section.
Trio is in Binary form. The formal scheme is:
[: A (68-75) :] [: B (76-91) : ] Codetta (92-95)
The A section consist of 4+4 sentence which modulates to A flat major (V).
The B section starts in A flat major and has secondaries to D flat and G flat Major. It ends with a PAC in D flat major. A four bar codetta shortly brings back the melody of Scherzo. Since there is “da capo” to Scherzo, the role of the codetta is to link Trio to Scherzo.