subsemitone

Subsemitone is an interval smaller than a semitone, a term used primarily in microtonal music. In standard Western tuning, the semitone is about 100 cents; a subsemitone is typically around 50 cents in a 24-tone equal temperament, effectively half of a 12-tone semitone.

In microtonal tunings such as 24-TET, the octave is divided into 24 equal steps, and a subsemitone corresponds to one of these steps. This division provides pitches between the familiar 12 equal divisions, creating a continuum of pitch not available in conventional 12-TET.

Notationally, subsemitones are indicated with microtonal accidentals such as half-sharps or half-flats in some notation systems. For example, the interval from C to C half-sharp is a subsemitone above C. Different tuning schemes may use alternative spellings, depending on their tonal or theoretical conventions.

Usage and context vary. Subsem tones appear in experimental and contemporary music, as well as in discussions of non‑Western tuning systems and theoretical explorations of microtonal intervals. They are one of several terms used to describe intervals that lie between the traditional semitone and adjacent pitches, and they are distinct from the conventional diatonic and chromatic semitones found in 12-TET.

See also: microtone, quarter tone, 24-EDO, microtonal notation.