Interval categories for standard diatonic music
Unisons and octaves
Perfect unison and perfect octave
Chromatic semitone and diminished octave
Seconds and sevenths
Diatonic semitone and major seventh
Whole tone and minor seventh
Thirds and sixths
Minor third and major sixth
Major third and minor sixth
Fourths and fifths
Perfect fourth and perfect fifth
Augmented fourth and diminished fifth