Orchestration: Tutti or Solo

When performing this first movement, there are two main considerations. One is orchestration, where I consider whether a section is, to put it in extremes, either tutti or solo.

For example, I consider the opening up to the first beat of measure 8 as tutti. Then, from the second beat of measure 8 to the third beat of measure 10, I consider it solo. While the current example is very clear, there are some sections where it's unclear which it is. However, please divide them without worrying too much. The reason for dividing them is to create dynamic differences.

The first movement as a whole is not a piece that progresses towards a single peak point. Many of the same themes are merely repeated in various keys, so dynamics tend to become flat, and this division helps to avoid that.

Tonality

The other consideration is tonality. Within this first movement, identify points of clear articulation, specifically cadential (ending) sections, where a new key begins.

For example, in measure 27, the section that is likely solo begins with the theme in F-sharp. This section is in B minor and continues in B minor until measure 40. Even within this B minor section, there are dynamic differences (louder, softer), but the discussion becomes about what character differences one perceives compared to the opening D major.

When a new key appears, performers should vary the volume, sound quality, and timbre that they deem appropriate (you are free to make this judgment yourself). This makes the music much clearer. Avoid playing all keys in the same manner.