7th Chord Inversions

Review

This lesson assumes you are already familiar with building and identifying 7th chords.

To review 7th Chords go to Understanding 7th Chords.

Bass versus Root

It is always important to remember the difference between the bass and the root of a chord. The bass is the lowest note of a chord. The root is the lowest note of a chord when stacked in thirds. Just like a triad can be inverted, a 7th Chord can be inverted by making the bass a note other than the root.

Types of Inversions

Triad inversions and 7th Chord inversions are nearly identical. The only difference, other than the addition of a 7th, is that a 7th Chord has one additional inversion: 3rd Inversion.

Root Position

Root Position is when the bass (lowest note) in a 7th Chord (or Triad) is the root. Notice that a root position 7th Chord in close position (all three notes within an octave) will be stacked 3rds. This is identical to a root position triad, except it has a 7th.

1st Inversion

First Inversion is when the bass (lowest note) in a 7th Chord (or Triad) is the 3rd. We can make the root position 7th Chord, stacked in thirds as above, into a 1st inversion 7th Chord by moving the root up one octave. In other words, we invert it one time. Notice that a 1st inversion triad in close position will have a 2nd as the top interval.

2nd Inversion

Second Inversion is when the bass (lowest note) in a 7th Chord (or Triad) is the 5th. We can make the above first inversion 7th Chord into a 2nd inversion 7th Chord by moving the bottom note up one octave. In other words, we invert it a 2nd time. Notice that a 2nd inversion triad in close position will have a 2nd between the middle two notes.

3rd Inversion

Third Inversion is when the bass (lowest note) in a 7th Chord is the 7th. We can make the above 2nd inversion 7th Chord into a 3rd inversion 7th Chord by moving the bottom note up one octave. In other words, we invert it a 3rd time. Notice that a 3rd inversion 7th Chord in close position will have a 2nd between the bottom two notes. Remember: third Inversion is unique to 7th Chords as compared to Triads.

In all four of the above examples, the chord remains an E minor 7 chord. The only thing that changes is the inversion.

How to Identify the Inversion of a 7th Chord

Example 7th Chord

1. Stack the 7th Chord in thirds by moving notes up or down an octave. This will help you to determine the root position 7th Chord. In this example, we can move the bottom two notes up an octave to get it stacked in 3rds. We can now see that the 7th Chord is a C major 7th Chord.
     
2. Look at the original triad to determine the bass of the 7th Chord. In the example, the bass is a G.
3. Use the bass to determine the inversion.
   • Bass = Root: Root Position
   • Bass = 3rd: 1st Inversion
   • Bass = 5th: 2nd Inversion
   • Bass = 7th: 3rd Inversion
   In the example, the original bass was the 5th of the 7th Chord. Therefore, the 7th Chord is a C major 7th Chord in 2nd inversion.

How to Build an Inverted 7th Chord

Example: Build a 1st inversion D major 7th Chord.

1. Build the root position 7th Chord.
        
2. Place the correct note in the bass. A first inversion 7th Chord will have the 3rd in the bass.
        
Remember that it is not necessary to place the 7th Chord in close position unless you wish to do so. All that matters is that the correct note is in the bass.

---

Return to Writing Music Identifying 7th Chord Inversions