Text: The interval comprised by two notes written on adjacent lines or spaces. A major third has two whole tones, a minor third a tone and a semitone, and a diminished third a whole tone. The mode of a triad is determined by its third, as is the mode of a scale, since the sixth and seventh degrees are treated as variable in the harmonic minor and melodic minor scales. The diminished third is most often used as the inversion of the AUGMENTED SIXTH, INTERVAL, IMPERFECT INTERVAL

See Also:

Source: 21