Inversion of interval

Interval inversion refers to the process of lowering the top note of an interval by one octave or raising the bottom note by one octave to change the range of the interval. The interval after transposition still maintains its interval quality (such as major third, pure fourth, etc.), but the range may change.

In music, interval inversion means raising the lowest note in a set of notes by an octave. In this section, we will learn about interval inversion. The first example is to practice pure fifth interval inversion: C to G.
Invert this interval and move the lowest note C up one octave.
The result is a pure fourth interval: G to C
Next, perform pure fourth interval inversion: F # to B
Move the lowest note up one octave.
The result is a pure fifth interval: B to F #
Pure intervals always reverse to other intervals.
The fourth and fifth degrees will transform into each other
Invert major third intervals: C to E.
Move the lowest note up one octave.
The result is a minor sixth interval: D to C.
Now transpose the next third interval: E-G.
Move the lowest note up one octave.
The result is a major sixth interval: G to E.