In Beginning Chord Theory For Guitarists I showed you how to construct basic three note chords, get them on the fretboard, and understand their relationship to one another.
In this post we’ll talk about how to read extended chord symbols, meaning those 7’s, 9’s, 11’s, and 13’s you’ve probably run across. These chords add a lot more depth and complexity to your chord progressions than regular 3 note (triad) chords.
Ok, let’s dig into the most common, but complex extension you’ll see. The 7th chord. If you remember from the Beginning Chord Theory article, chords are built using every other note, ie A C E. The more general names for those notes are the root, 3rd, and 5th, denoting their interval above the root note. If we stack one more 3rd on that chord that would be the 7th, or the note that is 7 notes above the root. Remember to count the root note as “1”.
A C E G
D F A C
F A C E
B D F A
E G B D
C E G B
Now we haven’t discussed any major or minor intervals or chords here yet. We’re just using the general pitch classes. The previous post went over major and minor triads, so we’ll just concentrate on the 7ths here.
When you add one more note to the top of the chord that gives us exponentially more possibilities for the quality of that chord. Here’s our options:
Major triad, Major 7th
Major triad, Minor 7th
Minor triad, Major 7th
Minor triad, Minor 7th
Diminished triad, Major 7th
Diminished triad, Minor 7th
Diminished triad, Diminished 7th
Augmented triad, Minor 7th
Wow! That’s a bunch of stuff… Here’s the easy way to remember how 7ths work. A major 7 is the note a half step below the root. (Remember reciprocal intervals?) A minor 7 is a whole step below the root.
Let’s use the root note C and build each of the chords above:
C E G B – Cmaj7
C E G Bb – C7
C Eb G B – Cm(maj7)
C Eb G Bb – Cm7
Check out the symbols on those. The system is this: A letter by itself means “major”. So if you just see the symbol C, that’s means a C major triad. If we want it to be minor we have to put the little “m” next to it.
The 7 on it’s own means a minor 7. If we want it to be major we put “maj” next to it. In certain jazz notations you might see a triangle instead of “maj”. It means the same thing.
Let’s keep going with the next group:
C Eb Gb B – Cdim(maj7)
C Eb Gb Bb – C7(b5) aka C half diminished 7
C Eb Gb Bbb – Cdim7
C E G# Bb – Caug7
Once again, that 7 by itself means a minor 7. So in something like Cdim7, it’s the C triad that is diminished and the 7 is minor. The second one up there is an odd bird. In the classical music realm they use the half diminished marking which looks like a circle with a slash through it, like the “no” symbol. And of course there’s no key on my keyboard for that one. 🙂 The rest of the world tends to use the C7(b5) marking which is more descriptive and instructive. It tells you to play a C7 (C E G Bb) then flat the 5th (G becomes Gb).
To place these chords on the fretboard, do the same as you did with triads in the previous article. Or feel free to use the chord finder over in the right sidebar.
If you continue to add thirds on top of your chord, past the 7th, you’ll get 9, 11, and 13. For instance:
C E G B D F A
D = 9th
F = 11th
A = 13th
If we were to go up another 3rd past A, we’d end up back at the root, C. Having a 9, 11, or 13 also implies that the minor 7th is in there too. If the 7th is not called for you’ll instead see add2 (instead of 9), add4 (instead of 11), and 6 (instead of 13).
Also, with these extensions, the 9,11, and 13 will be the notes that are included in (diatonic) the scale of that chord. They can also be sharped and flatted. Here’s some examples:
D9 – D F# A C E
Dm9 – D F A C E
D7(b9) – D F# A C Eb
Dm(#11) – D F A C E G#
Once you have the hang of 7th chords, these extensions will be easier to understand. So make sure you’re solid on those first.
How To Practice These: Find a chord symbol you’d like to figure out and do your best to spell out the notes. Then go to the chord finder in the right sidebar here and look up that chord. Check your work against the notes the chord finder gives you and see if any of your notes were incorrect. If so, find out how that note was altered from what you expected it to be.
Sometimes there may be a note missing. That’s ok. We often leave out the 5th. And for larger voicings like 11 and 13 you may not see the 5th or 9th in there. The 13th in particular is a 7 note chord, but rarely played that way, especially because we only have six strings on a guitar. But a 13 can be implied with just the root, 3rd, 7th, and 13th.
My purpose here is to give some insight into how to translate a chord symbol into the actual notes of the chord and I hope it’s been helpful. Though this is a deep subject. Please feel free to leave me a comment below if you have any questions or if I skipped over something you’d like to know about.
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