Major Scale Harmony And Chords

What You Should Already Know

• All twelve Major scales
• How Major scales are built.

Motivation

The motivation for understanding Major scale harmony in relation to chords is in its application to ear training and composition.  For the most part, western music centers around Major scale harmony.  A large portion of chords in any song composed in a Major key will use chords found in Major scale harmony.  Of course, there are songs out there that use many outside chords, so don't be surprised when you come across them.

Knowing this helps speed up the process of learning to play by ear.  If you are in the key of C and the bass player plays a D, then most likely the chord being played is a D minor (this will be explained). Understanding Major scale harmony allows you to quickly identify most of the chords in a song.

In composition, understanding Major scale harmony is useful in composing songs that have a solid harmonic grounding.

Introduction

As you know, Major scales are built with seven notes according to the following pattern:

    Root-Whole Step-Whole Step-Half Step-Whole Step-Whole Step-Whole Step-Half Step (Root)

It is because of this consistent pattern, regardless of the root, that we can say, without doubt, that all I chords of Major scales are Major.  In this same manner, we can discuss the other chords that belong to all twelve Major scales.

It is important to understand the methodology for building chords.  Every chord begins with a root.  Major or minor thirds are then stacked on top of this root to build a chord.  For example, a Major chord is built with a Major third from the root and a minor third from there.  An even clearer example is C Major:  C is the root, C to E is a Major third, and E to G is a minor third.

In building chords, scale harmony (not just Major scale harmony) dictates that we only use notes from the scale that we are in.  These are called diatonic notes.

Here is a quick review before we dive in:

• All Major scales are built using the same pattern.
• All chords are built by stacking Major and minor thirds.
• All chords are built with diatonic notes.

Triadic Major Scale Harmony

Let us look at triadic Major scale harmony with relation to the key of C Major (triadic:  three-note chords):

These scale-step chord types will remain the same for all Major scales.  The nomenclature for generalizing the scale-steps is roman numerals.  Uppercase roman numerals are used for Major chords and lowercase roman numerals are used for minor chords.

As discussed in the motivation for understanding Major scale harmony, knowing the chord types by scale-step can help when playing by ear. The example given was a bass player playing a D while you are in the key of C Major.  D is the second scale-step and from the table above we learn that it is very likely a D minor.

Seventh Chord Major Scale Harmony

Of course rarely play just triads.  Jazz especially centers around the use of seventh chords and Gospel to a lesser extent.  Let us look at seventh Major scale harmony with relation to the key of C Major:

Some people call the vii(b5) a vii half-diminished.

For the sake of simplicity, we use the first set of roman numerals, it being understood that a I chord is always a Major 7th, a ii chord is always a minor 7th, a iii chord is always a minor 7th, etc.  You should also simplify vii-dim to vii.

Exercise

Write out a chord chart to a song that you know the chords to.  Determine the key of the song and write out roman numerals above all chords that are part of the key that you are in.  For example, if the song is in the key of C, you will be looking for the chords in the tables above.  If a chord isn't from that key, then don't write anything above it.

Note:  Any chords that don't come from the key that you're in are from other keys.  Many songs will modulate to another key for a measure or two to introduce chords that add color to the song.  Think about what keys your song may have modulated to.

Exercise Example

"Amazing Grace"

Key:  F Major

I                               IV           I                vi          ?               V
F                              Bb          F              Dm7     G7             C7
Amazing grace, how sweet the sound that saved a wretch like me.

I                             IV          I                 vi            ?     V     I
F                            Bb         F               Dm7       G7   C7   F
I once was lost, but now I'm found; was blind, but now I      see.

This is a basic version of "Amazing Grace" in the key of F Major.  Notice that most of the chords fit into Major scale harmony.

You will also notice that there is a lot of emphasis on the I, IV, and V.  The three most important chords in any piece of music are the I, IV, and V.  Everything else is there to support and move between these three chords.  If you study and pay close attention to the various ways of moving between these three chords, then you will learn many ways to make your music sound interesting.

As for where the G7 comes from, the strongest explanation is that it is acting as the V chord of the key of C Major (although a C7 is used instead of a C Major).  It would then follow that the Dm7 is a transitional chord that moves you to the key of C Major, for Dm7 is found in both the key of F Major as the vi and C Major as the ii.  So we see that "Amazing Grace" takes a short vacation to the Major key a fifth above (or a fourth below) the key of F Major for added interest.  You could skip this vacation altogether by playing a Gm7 instead of a G7, thus staying completely in the key of F Major.

Conclusion

The more times you repeat the exercise, the more mileage you'll get out of understanding Major scale harmony and its application to chords.  The application of Major scale harmony to chords doesn't stop at seventh chords though.  There is much discussion that can be given to extensions: ninths, elevenths, and thirteenths.