In the exposition of a Classical sonata form, where is the second subject typically presented?

• A. In the relative minor or dominant key
• B. In the tonic key
• C. In the parallel major key
• D. In the subdominant key

Answer: (A)

In the exposition of Classical sonata form, the purpose is to introduce two main musical ideas in two different keys, creating clear contrast and momentum. The first idea stays in the home key to establish the tonal center, and the second idea moves to a different key to give variety and propel the music forward.

The second subject is typically heard in a key that is not the tonic. In pieces written in a major key, that contrasting area usually unfolds in the dominant key, which provides strong harmonic pull toward a cadence and sets up a smooth path into the development. When the work is in a minor key, composers often shift the second subject to a related tonal center that offers brightness and contrast—often described as the relative major or another distinctly related key—before returning to the home tone in the recapitulation.

This placement of the second subject in a non-tonic key is what gives the exposition its balanced sense of departure and return, and it explains why the second theme is heard in a key closely related to the home key yet clearly different from it.