# semitone

(redirected from*Pythagorean diatonic semitone*)

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## semitone

an interval corresponding to a frequency difference of 100 cents as measured in the system of equal temperament, and denoting the pitch difference between certain adjacent degrees of the diatonic scale (

**diatonic semitone**) or between one note and its sharpened or flattened equivalent (**chromatic semitone**); minor second## Semitone

the smallest interval in European music. In the modern system of temperament, all semitones are equal, and there are 12 semitones in an octave.

There are three types of semitones: diatonic, chromatic, and enharmonic. The diatonic semitone is an interval between adjacent steps of a scale (for example, B to C, D to E flat [a minor second]). The chromatic semitone is the interval between a foundation and its raised or lowered variant (for example, F to F sharp, an augmented prime). The enharmonic semitone is the interval formed by the alteration of adjacent steps—for example, F double sharp to A flat, a double-diminished third (*see*INTERVAL).

## semitone

[′sem·i‚tōn] (acoustics)

The interval between two sounds whose frequencies have a ratio approximately equal to the twelfth root of 2. Also known as half step.