In 12-tone method, what does the composer ensure about pitch classes?

• A. Each of the twelve pitch classes appears exactly once before any repetition.
• B. Pitch classes are chosen to emphasize the tonic.
• C. Only diatonic pitches are used.
• D. The melodic contour is symmetrical.

Answer: (A)

In the 12-tone method, the organizing idea is that all twelve chromatic pitch classes are heard before any one of them is repeated. The composer creates a tone row that includes each of the twelve pitch classes exactly once in some order, and that row becomes the basis for the piece. From that row, music is generated through transformations like transposition, inversion, retrograde, and retrograde inversion, keeping the original set’s equal treatment of all tones. This approach prevents establishing a tonal center, since no single pitch class dominates the opening material. It’s not about emphasizing the tonic, nor about using only diatonic pitches, and symmetry of melodic contour is not a required feature.