Interval

Criterion: number of half-steps

• ≤ 12: Simple Intervals

0: Unison

1: Minor Second

2: Major Second

3: Minor Third

4: Major Third

5: (Perfect) Fourth

6: Tritone

7: (Perfect) Fifth

8: Minor Sixth

9: Major Sixth

10: Minor Seventh

11: Major Seventh

12: Octave

 

• > 12: Compound (Extended) Intervals

  13

  14: Major Ninth

  15

  16

  17

  ......

Relationships among intervals:

(Xth) and (9 - Xth): Inversions

• 2nd /7th
• 3rd/6th
• 4th/5th