Editing Interval (music) (section)

==== Major and minor ====
[[Image:Major and minor intervals on C.png|thumb|Major and minor intervals on C: {{audio|Minor second on C.mid|m2}}, {{audio|Major second on C.mid|M2}}, {{audio|Minor third on C.mid|m3}}, {{audio|Major third on C.mid|M3}}, {{audio|Minor sixth on C.mid|m6}}, {{audio|Dim seventh on C.mid|M6}}, {{audio|Minor seventh on C.mid|m7}}, {{audio|Major seventh on C.mid|M7}}]]
As shown in the table, a [[diatonic scale]]{{efn|name=diatonic}} defines seven intervals for each interval number, each starting from a different note (seven unisons, seven seconds, etc.). The intervals formed by the notes of a diatonic scale are called diatonic. Except for unisons and octaves, the diatonic intervals with a given interval number always occur in two sizes, which differ by one semitone. For example, six of the fifths span seven semitones. The other one spans six semitones. Four of the thirds span three semitones, the others four. If one of the two versions is a perfect interval, the other is called either diminished (i.e. narrowed by one semitone) or augmented (i.e. widened by one semitone). Otherwise, the larger version is called major, the smaller one minor. For instance, since a 7-semitone fifth is a perfect interval ('''P5'''), the 6-semitone fifth is called "diminished fifth" ('''d5'''). Conversely, since neither kind of third is perfect, the larger one is called "major third" ('''M3'''), the smaller one "minor third" ('''m3''').

Within a diatonic scale,{{efn|name=diatonic}} unisons and octaves are always qualified as perfect, fourths as either perfect or augmented, fifths as perfect or diminished, and all the other intervals (seconds, thirds, sixths, sevenths) as major or minor.