When I first heard this piece, I had the impression that it was precisely like a certain French film score. Of course, this one is the original. The progression sometimes includes chromatic movement, possessing a shadow within its beauty, not optimistic, and even without a distinct melodic line, it is a movement that creates a unique atmosphere.

I would like you to divide this piece into several parts, grasp the cadences, and vary the volume and tone quality based on each section, or each key, or the chord progression, but this piece ends in E minor, and the next movement also begins in E minor (although the key signature is B minor, the key determination is E minor).

Both E minor and B minor, as keys used by Bach, might fall into the category of relatively subdued keys. B minor still possesses an optimistic aspect, but especially in the case of E minor, there is a unique shadow and sadness, which is slightly different from strong emotional expression. Therefore, although you might be tempted to increase the volume when the notes are in a high register, it is advisable to keep it somewhat restrained.