Diatonic \Di`a*ton"ic\, a. [L. diatonicus, diatonus, Gr. ?, ?, fr. ? to stretch out; dia` through + ? to stretch: cf. F. diatonique. See Tone.]

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

Diatonic scale (Mus.), 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.

Source: Webster's Revised Unabridged Dictionary (1913)