Inversions

Interval Inversions

To invert an interval is move the root note to the top. Effectively viewing the previous top note from its lower octave, e.g C → E is now E → C. In the example below, the type of interval changes from Major 3rd to Minor 6th (Interval Size: 9 - 3 = 6, Quality: Major → Minor). This is very helpful for finding the location of an interval an octave above/below and create more interesting music.

Tips:

• The Rule of 9 (Interval Size): Subtract the original interval number from 9 to determine its inversion.
  • Unison ↔ Octave
  • Second ↔ Seventh
  • Third ↔ Sixth
  • Fourth ↔ Fifth
• Quality Changes: The quality of an interval changes to its opposite when inverted.
  • Major intervals become minor (and vice versa)
  • Augmented intervals become diminished (and vice versa)
  • Perfect intervals remain perfect

Interval	Inversion	Diagram
Minor 2nd	Major 7th
Major 2nd	Minor 7th
Minor 3rd	Major 6th
Major 3rd	Minor 6th
Perfect 4th	Perfect 5th
Perfect 5th	Perfect 4th
Minor 6th	Major 3rd
Major 6th	Minor 3rd
Minor 7th	Major 2nd
Major 7th	Minor 2nd

Note: Because a tritone divides the octave into exactly two equal halves (six semitones), it is perfectly symmetrical and is the only interval that inverts to itself.

Exercises

• Ascend a scale from root to octave using intervals, e.g. in C Ionian C → D, C → E, etc. Then descend from the root’s octave in the same way. Recognize the inversion.
  • At first, you may want to focus on a few intervals and try making music with them.

Related

• Intervals

Triad Inversions

Triad Inversions, or chord inversions, have 2 variations. 1st inversion moves the root note to the top, e.g. C - E - G becomes E - G - C. 2nd inversions moves the fifth to the bottom, e.g. C - E - G becomes G - C - E.

Major

1st Inversion	2nd Inversion

Minor

1st Inversion	2nd Inversion

Practicality

Here is a practical usage of triad inversions, at least within diatonic music. Consider these guidelines when moving through Chord Progressions:

• 2nd and 7th do not share any notes and you retain the same chord shape
• 4th and 5th share one note
• 3rd and 6th share 2 notes

Notice that, by using inversions instead of only root shape, you can move more efficiently (staying in the same area on the neck) and create a more interesting sound.

For example, in a I | vi | IV | V in C Major:

1. Play root at the bottom –> C E G
2. Play vi in 1st Inversion –> C E A
   1. vi is I’s 6th, thus share two notes and you only need to move 1 finger.
3. Play IV in 2nd inversion –> C F A
   1. IV is vi’s 6th, thus share two notes and you only need to move 1 finger.
4. Play V in 2nd inversion → D G B
   1. V is a 2nd of IV, thus don’t share notes and you need to move all your fingers while staying in the same chord shape.

Bonus: If you wanted to close at I from the V, since I is V’s 4th, you should share one note and play the I in 2nd inversion and two fingers move → G C E

Exercises

• Figure out inversions across 2 strings.
• Figure out inversions for diminished and augmented triads
• Pick a tonic and move through different intervals with an appropriate inversion
• Switch inversions on the fly as you loop a chord progression