Rounded binary form is characterized by which sequence?

• A. A B B A
• B. A B A
• C. A A' A
• D. A A B

Answer: (C)

Rounded binary form centers on returning to the opening material after the contrasting section, usually with some modification, which gives a sense of closure or “rounding off.” The sequence that best shows this is A A' A: you begin with the initial theme (A), come back to that material in a varied form (A'), and finish with a final restatement of the opening theme (A). The variation in the return (A') is what distinguishes rounded binary from a plain A B A pattern, where the return of A isn’t specifically altered. The other patterns don’t depict that emphasized, varied return of the opening material after the middle section.