Chords, Riffs, 12 Bar Form
The origin of indigenous Americana Country, Hillbilly, Blues, Folk styles are not an overt adaptation of the Western “Common Period” classic tradition.This predominantly rural development began and was sustained on homemade instruments with 1 to 3 to 4 strings. Many, if not most 3 string cigar box instruments are tuned to the notes D G D. To think this tuning, Root 5th Root, is the fundamental chord of heavy metal is indeed interesting. Notated as G5.
The essential feature of this G5 chord is that there is no 3rd. Therefore it can function as either a G Major or a G minor. It is also termed a “Dyad, Power Chord, Double Stop.”
This distinguishes the chord from the Western Tradition as two notes are not recognized as a chord. The caveat here is that acoustic perception studies tend to show that the brain "fills in" the major 3rd when a power chord is heard.
On a 3 string instrument this tuning produces a 3 note mini “Barre” chord that can be slid or placed anywhere on the neck.
This means that any song’s chord progression may be played with just this 3 note “Barre” by placing it on different frets. This is “Ear” music and to defuse the initial tendency to over intellectualize we will reduce our focus to these 3 main areas -
Chords, Riffs and 12 Bar Form
In Western tradition any Major Diatonic scale produces 2 major 7th chords, 3 minor 7th chords, 1 Dominant chord, and 1 minor 7 flat 5 chord.
C Major scale C D E F G A B, by skipping every other note, produces Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7flat5.
Disregard all that.
Eliminate the 7ths and pull out just C, F and G. These may be used as is and are commonly referred to as “Cowboy Chords.”
Now here is where Blues self identifies and distinguishes itself.
Pull out the G7 chord, then make Cmaj into C7, Fmaj into F7.
This leaves C7, F7 and G7. These 3 Dominant chords are the I IV V chords used in Blues songs.
(C7, F7, G7 is the key of C) (A7, D7, E7 is the key of A) (D7, G7, A7 is the key of D)
(E7, A7, B7 is the key of E) (G7, C7, D7 is the key of G)
Bear in mind you can always eliminate the 7ths and play simple major chords, especially if the vocalist or lead instrument is targeting the 7ths in the melody.
RIFFS
Yes there is a scale called the Blues scale, but it was over time that it achieved this recognition. If you consider that a scale is, by definition, a linear presentation of notes… and a chord is a vertical stacking by 3rds of the same scale notes, then it follows that “there are only chords” as the Louisiana boogie pianist exclaims.
So what is a Riff? A Riff is a subset of notes that is played like a mini scale that reenforces specific chord tones.
There exists a “vocabulary” of Blues Riffs that have become standardized for each of the I IV V chords.
Once you realize that chord tones as targets are the basis of this vocabulary you can easily begin creating your own additions to your personal repertoire. In its simplest terms the bass targets the Root and 5ths. Guitar targets the 3rd and 7ths. Dividing up the chords between instruments creates space. This is not to say that everyone pounding on the roots is not an effective experience.
12 Bar Form
This is a Universal chord progression that is the basis of perhaps 80% of Blues songs. There are several variations but they seldom affect the total 12 bar form. Here is the basic 12 bar chord progression broken into 3 sections. Roman numerals I IV V are used so one may insert any key.
I
//// //// //// //// Section 1
IV I
//// //// //// //// Section 2
V IV I V
//// //// //// //// Section 3
Refer back a page to key examples and then plug in simple chords without the 7ths.
I = C IV = F V = G Key of C
I = A IV = D V = E Key of A
I = G IV = C V = D Key of G
I = D IV = G V = A Key of D