Scale

A sequence of notes in ascending or descending order of pitch. It is long enough to define unambiguously a mode or tonality and begins or ends on the fundamental note of that mode or tonality. A scale is DIATONIC if the sequence of notes is based on an octave species consisting of five tones and two semitones; the MAJOR and natural MINOR scales are diatonic, as are the church modes (see MODE). A CHROMATIC scale is based on an octave of 12 semitones. The WHOLE-TONE SCALE proceeds entirely by whole tones. A PENTATONIC scale has five pitches within the octave.