Hi Campers. Welcome to the final installment of my series on guitar fretboard logic. Last post, I talked about eleventh and thirteenth chords. At this point, if we extend the major scale any further, we would just be repeating notes. But we have been limiting our discussion to notes that occur naturally in the major scale. I’m not going to get into the construction of major scales, there’s a zillion music theory sites that can explain it but suffice to say that notes that are in a given major scale are said to be diatonic to the scale. So what about chords using tone colors that are not in the parent scale. We’re now talking about altered chords.
Let’s backtrack for a moment. When we get to seventh chords, there are three notes that really define the nature of that chord: the root, the third and the seventh. They determine the basic tonality, if the chord is major 0r minor and if it’s a major seventh or a dominant seventh. So we have the first, third and seventh notes of the scale accounted for. That leaves the second (or ninth), the fourth (or eleventh), the fifth and the sixth (or thirteenth). You can sharp or flat those notes, thereby altering them, and still maintain their basic character as a major or minor or dominant chord.
Every now and then I come see altered minor harmony but for the most part, I see altered chords based on major seventh and particularly, dominant seventh chords. The most common altered major seventh chord you will come across is the major seventh #11 chords. The formula for the chord is root, third, fifth. seventh and #11 of the major scale.
Scale Step : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
C major scale : C D E F G A B C D E F G A B C
Chord tones: 1 3 5 7 #11
C Major 7 #11: C E G B F#
As I stated previously, when you play the diatonic eleventh, you are rubbing against the major third of the triad. You raise the eleventh interval by a half step (or one fret) to a #11 to mitigate the dissonance of that rub. The #11 does occur naturally in major seventh chords based on the fourth note of the major scale. That gets us into the topic of chords based on the harmonized major scale but that’s the basis of another series of posts that I will get into at a later date.
I tend to visualize the #11 as being one fret lower than a chord’s fifth (see diagram 1A). Many common grips of major 7 #11 chords actually replace the chords fifth with the # 11 to facilitate easier fingering (see diagram 1B).
Diagram 1A
Diagram 1B
When you get to altered dominant seventh chords, you’re getting the whole kettle of fish. There’s seventh b9 chords, seventh #9 chords, seventh #11 chords, seventh flat 13 chords, seven flat 5, seven #5, combinations of the above and others. Why do you see so many altered dominant seventh chords? In functional harmony, the dominant seventh chord signifies the point of the most tension in a given key. The dominant chord is usually built on the fifth degree of the scale and there is a very strong pull to resolve this tension by following the dominant chord (the V chord) with the chord built on the first degree of the scale (the I chord, also known as the tonic). It all comes down to tension and resolution. By chromatically altering the V chord, you are essentially doubling down on the harmonic tension in the chord progression which will be resolved when you get to the tonic chord.
At this point, I was hopefully clear enough in the previous posts for you to be able to figure out where you can locate the b9, #9, #11, b13 of any given chord anywhere on the guitar neck. A b9 is one fret above the chord root. A #9 is enharmonically synonymous (again with that tongue twister) with the flat third and is one fret lower the the major third. The b13 can be seen as one fret higher than the chord’s fifth. Basically it all comes down to this: If you know the five major triad chord shapes that cover the guitar fretboard and where the chord’s root, third and fifth are, you can extrapolate where all the other chord tones (diatonic and chromatic) are. I feel that this way of knowing the guitar neck will help your playing in the long term much more than memorizing scale patterns.
This series all started when some asked me what scales I use when improvising. This made me think about how I actually viewed the fretboard and I realized that I think in terms of chords rather than scales. I thought it might be helpful to others to share these thoughts and I hope it has.
RoyMusicUSA 
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