Diatonic /(dī`ȧ*tŏn"ĭk)/

Di·a·ton·ic

Diatonic

a.
  1. Pertaining to the scale of eight tones, the eighth of which is the octave of the first. (Mus.)

Phrases & Compounds
Diatonic scale
a scale consisting of eight sounds with seven intervals, of which two are semitones and five are whole tones; a modern major or minor scale, as distinguished from the chromatic scale.