We have covered the “box” for the 3rd and the “add” chords where we have a space in the box where the 6th or 7th resides. This time, we will look at what happens when we fill the box for the 6th or 7th with a note.
Before we go further this time, we must discuss how the 6th and 7th are written within a chord name. Music theory is based around the Major scale, and the Major version of scales and chords are used as the base. From there, the deviations from the Major are highlighted to give us the chords.
For the 6th chord, this means it is the Major 6th that is used as default. If we have a minor 6th chord, it is only the 3rd that is flattened, and the 6th is a Major 6th unless otherwise stated. If we extend the chord and include the 9th or 11th, we have a 6/9 or a 6/11 chord. The 6 is included to identify the 6th is used and not the 7th.
The 7th is the default for use in this box, and there is a significant change to the way the 7th is expressed that must be addressed. The default for the 7th when in a chord name is the b7, not the Major 7, with excellent reason. If we look at a C7 or Cmaj7 chord, the degrees of each chord is
Cmaj7 1 3 5 7
C7 1 3 5 b7
Surely these chords should be written as C7 and Cb7?
However, would the Cb7 be a C with a b7 or a Cb 7 chord?
To ensure the correct chord is used, we use the 7 to indicate the b7th and the Maj7 to indicate the 7th.
By default, when we see a 9, 11, or 13 chord, it has the b7 included. If there is no 7th, it has the “add” as discussed before. When we see Maj9, Maj11, or Maj13, it is the 7th and not the b7.
Let us look at our five open chord shapes again.
As before original chord tones are in red.
We use the 2nd string as the box for the 7th of the chord, and the root can be moved down to create the 7, b7 or 6. Giving us the Chords Dmaj7, D7, and D6
For the A, we can use the 3rd string as the box for the 7th and move the root down to get the 7 and b7. Giving us Amaj7 and A7
Alternatively, we can use the 1st string as the box and move up from the 5th to give us the b6, 6, b7 and 7. Now we have two voicings of Amaj7 and A7 plus new chords of A6 and Ab6.
For the E chord. We can use the 4th string as the box for the 7th, giving us the b7 and 7. Giving us the Emaj7 or E7 chords
We can use the 2nd string and go up from the 5th to give the b6, 6, b7, and 7. Like the A chord, now we have two voicings of Emaj7 and E7 plus new chords of E6 and Eb6.
For the C, there is an overspill when moving up from the 5th due to the guitar’s tuning. With the box on the 3rd string, we get the b6, 6, b7, and 7th and the Cmaj7, C7, C6 and Cb6 chords.
We can also go down from the root note on the 5th string and get the 7, b7, and 6 giving us a 2nd voicing for Cmaj7, C7 and C6.
For the G, we use the 1st string as the box and move down from the root not to give us the 7, b7, and 6. Giving us the chords Gmaj7, G7, and G6.
We can also use the 4th string as the box and move up from the 5th to give us the b6, 6, b7, and 7 and the Chords Gb6, G6, G7, Gmaj7.
In this case, I have included the 5th on the 2nd string for reference as adding the 5th back in can be worthwhile depending on the song’s context.
We have only the 5th to look at before joining all this together. Keep looking at the songs you play and the chord shapes being used. Visualising and hearing where these notes come from is essential to your creativity.