Harmonizing the Major Scale
The Basics:
Most chord progressions that you will come across are based on a formula. That formula is the harmonized major scale, or what I call the CHORD SCALE. There are exceptions to this statement, but usually, those exceptions can be traced back to the harmonized major scale as well.
If we take the major scale:
C - D - E - F - G - A - B - C
And we build a triad off of each note of the scale using only notes found within the scale, we get this:
I C-E-G
1-3-5Cmaj ii D-F-A
1-b3-5Dmin iii E-G-B
1-b3-5Emin IV F-A-C
1-3-5Fmaj V G-B-D
1-3-5Gmaj vi A-C-E
1-b3-5Amin vii B-D-F
1-b3-b5Bdim VIII C-E-G
1-3-5Cmaj This is where the Roman numerals come into play. By referring to the Roman numerals, we can talk about chord progressions without having to dictate the key. For example, a very common chord progression is I-IV-V-I. This progression is used in a lot of songs.
Let's look at the chart again:
I C-E-G
1-3-5Cmaj ii D-F-A
1-b3-5Dmin iii E-G-B
1-b3-5Emin IV F-A-C
1-3-5Fmaj V G-B-D
1-3-5Gmaj vi A-C-E
1-b3-5Amin vii B-D-F
1-b3-b5Bdim VIII C-E-G
1-3-5Cmaj I-IV-V-I means to play the chord built off of the first degree (note) of the scale followed by the chord built from the 4th degree, the chord built off of the 5th degree and back to the chord built off of the 1st degree. In the key of C, that would be C-F-G-C.
To play the progression in another key, you need to know the chord scale for the key you want to play in. That sounds like you have to know a different chord scale for every key, but it is much easier than that.
Let's look at the key of G:
I G-B-D
1-3-5Gmaj ii A-C-E
1-b3-5Amin iii B-D-F#
1-b3-5Bmin IV C-E-G
1-3-5Cmaj V D-F#-A
1-3-5Dmaj vi E-G-B
1-b3-5Emin vii F#-A-C
1-b3-b5F#dim VIII G-B-D
1-3-5Gmaj Notice that we get the same TYPES of chords in the EXACT SAME ORDER as before. The only thing that changes is the root notes of each chord and the notes in each chord follow the G scale instead of the C scale. No matter what key we choose, the chord types will occur in the exact same order so long as we follow the major scale in that key. (if we use a different scale, then the chords will be different.)
What this means to you, is that all you have to learn is which number = which chord type and how far apart the chords are from one another. It's really easy!
The major scale follows this whole-step/half-step pattern:
w - w - h - w - w - w - h
The chord scale follows the same pattern:
I ii iii IV V vi vii VIII w w h w w w h Now, all you have to do is remember which type of chord each number represents.
I ii iii IV V vi vii VIII w w h w w w h maj min min maj maj min dim maj Notice that upper case numerals are used for major chords and lower case for minor and diminished. This is to help you keep the chord types straight.
There is an old system for naming each chord within the chord scale, and some people insist on using it. I figure that I better show it to you, so you won't feel left out:
I Tonic ii Supertonic iii Mediant IV Subdominant V Dominant vi Submediant vii Leading Tone You will here the word "dominant" thrown around quite often. The others you may never run into, but you never know.
The Fingerboard:
Key of F, using barre chords:
I - Major
ii - minor
iii - minor
IV - Major
V - Major
vi - minor
vii - diminished
VIII - Major
Key of C, using "cowboy" chords:
I - Major
ii - minor
iii - minor
IV - Major
V - Major
vi - minor
vii - diminished
VIII - Major
The Practice:
The first thing you need to do is play up and down the chord scale in EVERY key. There is no substitute for this practice. You gotta be able to see the chord types and the w/h-steps no matter where the chords land on the fingerboard. The more chord shapes and inversions that you know, the more you need to play through the chord scale using those shapes.
Next, take every chord progression that you know (and every one that you learn from now on) and see if the chords fit the chord scale.
A few of points to keep in mind:
1 - A lot of progressions are based around chord I, but any chord in the scale can be the main chord of a song. For example, V-IV-I-V and vi-IV-V-vi are two very popular rock progressions. ii-V is a popular jazz progression. These three progressions don't even use the I chord!
2 - very few songs use the entire chord scale. They usually just use part of the chord scale.
3 - A song doesn't have to stay in one key. If you run into a progression that doesn't seem to fit the scale, you might be looking at chords for more than one key mixed together.
4 - There are a lot of variations on this chord scale that are common practice. Some progressions will substitute major chords for minor chords or vice-versa. Some progressions will borrow chords from other scales or keys and throw those into the mix.
