This creates a linear pitch space in which octaves have size <answer>1</answer>2, semitones (the distance between adjacent keys on the piano keyboard) have size <answer>1</answer>, and A440 is assigned the number 69. (See Frequencies of notes.) Distance in this space corresponds to musical intervals as understood by musicians. An equal-tempered semitone is subdivided into <answer>1</answer>00 cents. The system is flexible enough to include "microtones" not found on standard piano keyboards. For example, the pitch halfway between C (60) and C♯ (6<answer>1</answer>) can be labeled 60.5.
Semitones in linear pitch are what size?
1