音程interval問題

方法一: 數半音 (count by semitones)
Major 2nd -------- 2 semitones
Major 3rd ---------4 semitones
Perfect 4th --------5 semitones
Perfect 5th --------7 semitones
Major 6th ---------9 semitones
Major 7th ---------11 semitones
Perfect 8ve -------12 semitones

Minor:
2nd (-1 semitone from major 2nd)------1 semitones
3rd (-1 from major 3rd)-------- 3 semitones
6th (-1 from major 6th)---------8 semitones
7th (-1 from major 7th)--------10 semitones

Augmented:
2nd (+1 semitone from major 2nd)------- 3 semitones
3rd (+1 from major 3rd)---------5 semitones
4th (+1 from perfect 4th)-------6 semitones
5th (+1 from perfect 5th)--------8 semitones
6th (+1 from major 6th)---------10 semitones
7th (+1 from major 7th)---------12 semitones
8ve (+1 from perfect 8ve)--------13 semitones

Diminished:
2nd (-1 from minor 2nd)------- 0 semitone, eg.C to Dbb
3rd (-1 from minor 3rd)--------2 semitones
4th (-1 from perfect 4th)-------4 semitones
5th (-1 from perfect 5th)--------6 semitones
6th (-1 from minor 6th)---------7 semitones
7th (-1 from minor 7th)---------9 semitones
8ve (-1 from perfect 8ve)-------11 semitones


minor 3rd 有3對半音, eg. D to F, 第一對半音係D to D#, 第二對係D# to E, 第三對係E to F.

major 3rd 有4對, eg. D to F#, 第一係D to D#, 第二係D# to E, 第三係E to F, 第四係F to F#.

F# to D, 8 semitones, so minor 6th.

C to D# 係 Augmented 2nd (3 semitones), 但是C to Eb 係 minor 3rd (3 semitones)