Pertaining to the scale of eight tones, the eighth of which is the octave of the first. 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.
Origin: L. Diatonicus, diatonus, gr, fr. To stretch out; through – to stretch: cf. F. Diatonique. See tone.