The presentation of a subject or theme with note values halved?

• A. Diminution
• B. Augmentation
• C. Inversion
• D. Retrograde

Answer: (A)

Diminution is rhythmic shortening of the note values in a theme, so the same melodic idea is presented more quickly while its contour and pitches stay the same. If the original uses quarter notes, a diminished version would use shorter values like eighth notes, halving the note lengths and speeding up the surface rhythm. This keeps the melody recognizable but compresses its timing.

Augmentation would do the opposite by lengthening durations, making the theme slower. Inversion changes the direction of intervals around a tonal center, altering pitch relationships rather than rhythm. Retrograde plays the theme in reverse order, again focusing on sequence rather than shortening note values. So rhythmic halving points directly to diminution.