# Chord Extensions

Discussion in 'Ask David Overthrow' started by joedecenso, May 16, 2011.

1. ### joedecenso

May 9, 2011
I'am a new memeber to this site. I started studying theory about 5-6 months ago and love it. I own all of your books, Beginning - Mastering, those books tought me alot of what I know and are an excellent tool. Having said that, I have a few questions. My question is about chord extensions. I have multiple books that talk about chord extensions and describe them as: You stack additional thirds to get chord extensions 9, 11, and 13. My question is, extensions 9, 11, and 13 are, as you know, scale degrees 2, 4, 6 transposed an octave higher. I found out something that contradicts the process of adding a third on top of a seventh chord. When I stack a third on a seventh (C maj 7) I get the note D# (8th fret on the G string) which is a half-step above D ( in the key of C major), the second scale degree. I found out that the distance from the seventh of the Cmaj 7 chord to the 9th is a flat third. The seventh is a F#. The second scale degree, transposed up an octave, is a D natural. I have noticed this in several other books as well, that these extensions are a third away. I'am I missing something? Why does this occur? Am I wrong?

2. ### metalstorm

Oct 13, 2005
You stack diatonic thirds. So for example in the key of C Major you have C to E which is a major third, E to G which is a minor third, G to B which is a major third B to D which is a minor third etc... You can tell if it will be major or minor depending on what the chord would be for that note. Once again in C major, E is the third chord which is Minor. Therefore you add a minor third. David can probably explain this better than me, but I hope that helps a little.

3. ### Art Araya

May 29, 2006
Palm Coast, FL
The 9,11,13 extensions for a CMaj7 chord are the notes D,F,A

The third could be a minor third or a major third. But it's got to be diatonic, or one of the notes in the key. In the key of C, a third above a B is a D. There is no D# in the key of C.

4. ### Dave Overthrow

Sep 12, 2006
Connecticut
Looks like the question has been answered. Thanks guys. How's it going Art?

As stated above, the diatonic chord extensions are simply the 2,4 and 6 scale degrees up an octave, which can be derived by stacking diatonic thirds. For example, if we stack diatonic notes from the note C the result is C,E,G,B, (chord tones), and if we continue, D,F,A, (upper extensions, tensions, chord extensions) many terms used for these tones.

It gets more interesting when you alter the upper extensions such as #11 on a major 7 chord, a b9 on a minor chord, b9, #9, #11, or b13 on dominant chords.

Check out those sounds.

5. ### joedecenso

May 9, 2011
Thanks for all your responses and info

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