Lesson 11: Diatonic Harmony - Part 1

Lesson Contents:

Harmonizing a Major Scale

In previous lessons we saw that when you play two notes at the same time you get something called an interval. What happens if you play more than 2 notes at the same time? Well, you get something that is called a chord. Where do chords come from? Well, chords come from scales. (Where else could they come from really?) For instance, to make diatonic chords from a major scale, we simply harmonize each note of the major scale with other notes from the same major scale. This process of harmonization is just a fancy name for stacking notes on top of each other.

For example, to make 3 note chords called triads, we place a diatonic 3rd and a diatonic 5th above each scale degree. If we harmonize the A major scale in this way, we get all the chords diatonic to the key of A major:

Diatonic Triads in A Major

If you repeat this process for every major scale, you will notice a pattern. The chords built on the 1st, 4th, and 5th notes of the scale will produce major chords. The chords built from the 2nd, 3rd, and 6th notes of the scale will all be minor chords. And the chords built from the 7th note of the scale will all be diminished chords. In short, we get 3 different kinds of triads when we harmonize the major scale.

A way to express this "harmonic analysis" among all major scales and keys is to use the following Roman numerals:

I     ii-     iii-     IV     V     vi-     vii°

An uppercase Roman numeral signifies a major chord, while a lower case number followed by a minus sign signifies a minor chord. (This is how I learned it at Berklee. There are other ways to notate this stuff, but this way seems to make good sense compared to other schemas I've come across.) A lower case Roman numeral followed by a degree symbol signifies an diminished chord.

You may be asking yourself, "What is a major chord or minor chord? How do they differ from each other? And, what the hell is a diminished chord, etc?" At least, I hope you are asking yourself these questions. The following section will attempt to answer these questions for you. Please note, if you haven't read my lessons on intervals, please do so before reading the rest of this lesson. I draw upon the concepts that were developed in those earlier lessons.

Triadic Formulas

So how many different kinds of triads are there? Only 4, but we can do a lot with them. The major scale only produces 3 of the 4 different kinds of triads. The other triad, an augmented triad comes from a different scale as we'll see later.

Here are the formulas for the 4 different triads:

Major: R 3 5
Minor: R b3 5
Diminished: R b3 b5
Augmented: R 3 #5

As you can see from the formulas, the only difference between a major triad and a minor triad is the third. That is, a major triad contains a major 3rd, while a minor triad contains a minor 3rd. They both contain a perfect 5th above their root. Please be aware that it is the 3rd of a chord that determines its quality - whether the chord is major or minor. I mentioned this in Lesson 5 already, but it's worth repeating.

Ex 1: A C major chord contains the following notes: C, E, and G, whereas a C minor chord (often abbreviated as Cm) contains the following notes: C, Eb, and G.

Ex 2: The only difference between a minor triad and a diminished triad is the 5th. For instance, in Cm we have C, Eb, and G, but in a C diminished triad (often abbreviated as C°) we have the following notes: C, Eb, and Gb.

Ex 3: The augmented triad contains a raised 5th. Often an augmented chord is notated using a plus sign. For instance, C augmented can be written as C+. It contains the notes: C, E, and G#.

Essential Chord Forms - Part 1

So, how do we play these suckers? Well, that's a simple question with a complex answer! First, I will show you some basic chord forms that are essential to every guitar player's vocabulary. Then we'll go from there. If you haven't figured this out by now, I use the natural notes on the low E and A strings of the guitar as a of "frame of reference" to help me get around. So here we go...

Essential Major and Minor Chord Shapes

Please pay attention to the fingerings in the above diagram. Also, please be aware of the X's denoting strings that are not to be played. If you ignore these, you'll get some weird sounding chords. I cannot stress to you how important these 4 chord shapes are to you. With them, you can play any major or minor chord on the guitar.

What about forms for the diminished and augmented chords? Well, here are a couple of forms to get you started:

Essential Augmented and Diminished Chord Shapes

Now an interesting phenomenon occurs. As you can see from the above diagram, the shape I drew for an augmented chord has 3 different uses. Any note of the chord can be the root! Why is this so? It is because an augmented triadic structure divides the 12 notes of music (introduced in Lesson 1) into 3 equal parts. That is, the distance between each note in any augmented triad (in close position) is a major 3rd or 4 half-steps. If we take this logic one step further we see that 3 divides 12 evenly giving us 4. This means that there are really only 4 different augmented chords instead of 12.

The Rationale... The augmented triad is a symmetric structure. That's why the same pattern can be used in different places on the neck of the guitar. This phenomenon is true for all augmented triadic structures. (It is also true for diminished 7th chords, a topic for a different lesson.) The shapes for an augmented triad all look the same and boil down to moving parts of the following pattern around on the guitar. Remember: any note in this pattern can be a root. This also implies that any note in the pattern can be a 3rd or a #5.

The Mother of All Augmented Chord Forms

The Gory Details... The 4 augmented triads (with their enharmonic spellings) are:

Chord Tones
(With Enharmonic Spellings)
Root 3 #5
1 C+ C E G#
E+ E G# B# (C)
G#+ G# B# (C) D## (E)
Ab+ Ab C E
Root 3 #5
2 C#+ C# E# (F) G## (A)
Db+ Db F A
F+ F A C#
A+ A C# E# (F)
Root 3 #5
3 D+ D F# A#
F#+ F# A# C## (D)
Gb+ Gb Bb D
Bb+ Bb D F#
Root 3 #5
4 D#+ D# F## (G) A## (B)
Eb+ Eb G B
G+ G B D#
B+ B D# F## (G)

This is a pretty complex chart full of enharmonic spellings. What you should get from this whole mess is that all 4 chords within one of the 4 categories are essentially the same chord. For instance, if you pick category #3 you will see that D+, F#+, Gb+, and Bb+ are the same chord because they are all comprised of the same 3 notes! They only look different because of the enharmonic spellings.

Putting It All Together - Triads In All Major Keys

With the above chord forms you can now play any diatonic chord (triad) for any major key. Remember Lesson 6? Lesson 6 showed us how to derive the notes for any major scale. With this information all we have to do is stack a 3rd and a 5th above each note of our major scale to get our diatonic triads. And that's it. Really! Then we use the simple fact that the I, IV, and V chords for all major keys are major triads; the ii-, iii-, and vi- are minor triads; and the vii° is a diminished triad. We get the following results:

Key The Diatonic Triads
I ii- iii- IV V vi- vii°
The Natural Key: C C Dm Em F G Am
Sharp Keys:
G G Am Bm C D Em F#°
D D Em F#m G A Bm C#°
A A Bm C#m D E F#m G#°
E E F#m G#m A B C#m D#°
B B C#m D#m E F# G#m A#°
F# F# G#m A#m B C# D#m E#°
C# C# D#m E#m F# G# A#m B#°
Key The Diatonic Chords
I ii- iii- IV V vi- vii°
Flat Keys:
F F Gm Am Bb C Dm
Bb Bb Cm Dm Eb F Gm
Eb Eb Fm Gm Ab Bb Cm
Ab Ab Bbm Cm Db Eb Fm
Db Db Ebm Fm Gb Ab Bbm
Gb Gb Abm Bbm Cb Db Ebm
Cb Cb Dbm Ebm Fb Gb Abm Bb°

Okay, this is what you should do: On a piece of staff paper write out all of the triads for all major keys just like I did at the beginning of this lesson with the A major scale. It's a great exercise to help you learn the note names in each chord. Afterall, if you know the note names for a major scale you then know the note names for all of the triads for that scale. More importantly, you should play these chords with the chord forms above. Use the Circle of 5ths to guide you through all of the major keys. You should also apply this approach to your major scales and pentatonic scales.

WARNING: Keep in mind that doing these exercises is not the same thing as making music. Instead, they are just a way to help you get the basics down which will hopefully establish a good foundation for you to not only understand music, but to make some new music of your own. Good luck.

Go to the next lesson, Lesson 12, or go back to the main menu.