Chord inversions are fairly straightforward, but easy to confuse at first! There are as many inversions as notes in a chord, so in a three note chord there are three inversions, a four note chord has four possible inversions and so on.
First we’ll look at the names of the inversions, then how they apply to three note chords then at four note chords.
The names of the inversions are very systematic. Just remember that these are like the floors of a building; the first floor is not at the bottom, just like the first inversion is not the root position of the chord.
Root inversion: root at the bottom (labelled a in the diagram)
First inversion: second note of the chord at the bottom (labelled b in the diagram)
Second inversion: third note of the chord at the bottom (labelled c in the diagram)
Third inversion: fourth note of the chord at the bottom (labelled d in the diagram)
Three note chords
Because these are only three note chords, they can only be in root, first or second inversion. So here are the notes of a C major chord in it’s various inversions:
Root inversion: C E G
Root inversion: C G E
First inversion: E G C
First inversion: E C G
Second inversion: G C E
Second inversion: G E C
You can see that it is the bottom note that is important. The following notes can be in any order, but only the note at the bottom affects the inversion.
Four note chords
The inversions of four note chords work the same as for three note chords, but there is another inversion possible; the third inversion. So as an example, let’s look at C7. I’ve only listed one spelling of the chord, as if I listed all possible spellings as I did above it’d make a very long list. So just keep in mind that the notes other than the one at the bottom of the chord might appear in a different order, but only the bottom note affects the inversion.
Root inversion: C E G B
First inversion: E G B C
Second inversion: G B C E
Third inversion: B C E G