A flat affects a note how?

A sharp raises a note, while a flat lowers a note. Accidentals in a measure last throughout the measure but can be canceled by a natural sign. Sharps and flats share a common pitch and are called enharmonic.

Explanation:

A sharp raises a note, while a flat lowers a note. Accidentals in a measure last throughout the measure but can be canceled by a natural sign. Sharps and flats share a common pitch and are called enharmonic.

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the answer is b. i'm positive it's that answer.

(a) i got it right on the test