9th/11th/13th Chords in a key

Hi everybody,

I am still trying to memorize all the chord shapes of all the extensions. What helped me a lot memorizing the shapes of the 7th chords was playing through all them as the chords in a key.

Leading me to the question; what are the chords in the key, for example for 9th chords and so forth? Is it like with the 7th chords?
1- Maj 9th,
2- Min 9th,
3- Min 9th,
4- Maj 9th,
5- Dom 9th,
6- Min. 9th,
7- Dim 9th ??? - does that even exist? :grimacing:

Thanks so much!

  • Kevin
1 Like

Kevin, unless you have specific songs where those chords are needed, do not set yourself the task of memorising 1000s of chord shapes. There are literally that many. Ted Greene publised a book ‘Chord Chemistry’ with nothing but thousands and thousands of chords. Unless you are called to play them somehow, learning them is a poor use of learning time.

As to your questions …

  1. yes
  2. yes
  3. yes
  4. yes
  5. yes
  6. yes
  7. not really - certainly not in practice.

See below for a chart showing the extensions you can make.

I have arranged it so that majors and minors show the increasing possiblilities going from 9th to 11th to 13th.
Note that the dominant just takes the number and the word dominant is unnecessary.
Note that a diminished basically has two forms in practice. Half diminished (also called minor 7 flat 5) and diminished (where the 7th note is a double flat). They are distinguished from one another by using a small circle (like a degrees sign for angles) where half diminished has a line through it and diminished does not.

1 Like

Hi Richard, yes you are 100% Right - it makes no sense to learn all shapes; I expressed myself poorly… I meant only one shape for e, a and d string each. They are used frequently in jazz and NeoSoul, so I wanted to learn these 27 shapes and that’s it. I encounter then all the time, and for me it makes sense to learn them “once and for all”. Your sheet is very helpful. Thank you so much!

1 Like

Makes sense.
You will be playing chord fragments on the thin strings which, in the context of a band, are viewed as 7th 9th, 21th or 13tf.

Nile Rogers does this a lot.

I should have made this point in regard to the chart. The further you extend the more you have options to dispose of notes that may be unnecessary.

For 7th chords you can dispose of the 5th.

For 9th the 5th also (not the 7th).

For 11th chords the 5th and / or the 9th.

For 13th chords the 5th and / or the 9th and / or the 13th.

1 Like

Thanks. Justin explains this in detail in his theory course. For me, I was only missing the “chords in the key part”, as i did not want to practice this wrong… :smile:

1 Like

Thanks for this Richard, but I believe we need an F#m11(b9) and Gmaj9(#11) in the key of D.

F#m11 = F# A C# E G# B
F#m11(b9) = F# A C# E G B

Gmaj11 = G B D F# A C
Gmaj9(#11) = G B D F# A C#

If we take the key of C to keep things ‘simple’, I think this is how we build diatonic chords for 7ths, 9th, 11ths and 13ths. The colors indicate extended notes that are flat or sharp relative to the diatonic chord.


Mind boggling stuff Jeff. Bravo and kudos for your attention to detail in pursuing an idea.

Hold on, it’s the other way round, no? We DO need those altered (and thus awful) chords to stay in the key of D. :slightly_smiling_face:

The b9 of an F#m chord is the note G, which is in the key of D.

Same thing for the #11 of a G chord: the note C# is also in the key of D.

Unless that’s not what you meant?

Jeff, my apologies. It seems I fell into a trap of my own making.
My previous will be updated.

1 Like