Descending Intervals

In order to create a descending interval, we use inversions of ascending intervals. Inverting the interval means moving the lower note up one octave, or the upper note down an octave. No pitch names change in this process. Once the inversion is found, you then revert the top note back to its position in the bottom resulting in the correct descending interval. There is a simple equation that can be used to find the inversion of an interval.

9-(quantity) down = opposite quality (quantity) up

Example: Minor 6th below C

9 - m6 down = M3 up

A Major 3rd above C is E. Therefore, a minor 6th BELOW C is E.

 

Chart of Quality Opposites:

Major

Minor

Minor

Major

Augmented

Diminished

Dimished

Augmented

Perfect

Perfect

*Note - a perfect interval has no opposite

Written examples:

Original

Inversion

M7

m2

P5

P4

m3

M6

A4

d5

 

Examples on the staff:

invertedintervals.gif Hyperlink to Flash Card Activity  

Compound Intervals

A compound interval is an interval larger than an octave. To determine the size of the compound interval, you can count all encompassing lines and spaces between the bottom and top note. Or - you can add the basic interval (i.e. "third) plus 7 (number of different notes in an octave).

Written examples:

A 9th is just a major 2nd plus an octave (2+7)

A 10th is just a major 3rd plus an octave (3+7)

An 11th is just a Perfect 4th plus an octave (3+7)

 

Examples on the staff:

compoundintervals.JPG