A piece divided into two sections labeled A and B is in which form?

• A. Rondo Form
• B. Binary Form
• C. Ternary Form
• D. Sonata Form

Answer: (B)

Two-part form is indicated when a piece clearly moves from a first section labeled A to a contrasting second section labeled B. In binary form, the music presents material in A, then shifts to B for contrast, often with a different key or mood, and then ends. This straightforward A–B structure is what makes binary form recognizable.

Rondo form, by contrast, centers on a recurring theme that returns multiple times across several sections, not just two parts. Ternary form uses three sections, typically A–B–A, with the initial material returning. Sonata form is a broader, more complex structure that unfolds through exposition, development, and recapitulation, involving multiple themes and developmental ideas rather than a simple two-part division.