Chord Structure...Basic Blues
Back to Goin' Down South
Imagine you are living in the late 1800s in the southern states of America. The main sound around you is European.
If you went over to the piano and poked the notes C, D, and E or sang “do, re, mi” you would be playing the first three notes in a major scale. On occasion you might want to change it up a bit and play an E-flat (Eb) instead of an E and call it a minor scale. How about C, D, E, F, and G, or “do, re, mi, fa, so”? Mmmmm, maybe you like playing those two notes C and G, and say, “that’s a perfect fifth!” To change it some more, you decide to play every other white note C, E, and G and think it sounds very nice. You’ll call it a C major chord (or a major triad). Throw in the seventh note, Bb, and you become very proud of your “seventh” chord.
However, make your way outside and you might be hearing a different sound altogether, a sound you were definitely not used to hearing, perhaps a more African sound. That interval between C and E is sounding very strange. You cannot tell if the black man playing the notes is trying to play and E or an Eb. He keeps slurring back from major to minor.
The man was also not playing that perfect fifth you liked so much. Instead, he was diminishing your sound by playing a Gb. “That’s not a note!” you’re thinking. “It’s scary, like devil’s music!” He continues to make you mad when he adds another note to your wonderful C major. So not only is bending the notes of G and Gb together, but he messes up the sound of your seventh chord by combining Gb with Bb.
Well, that’s a small example to understanding the notes played within a blues chord structure. The blues musicians figuratively and literally bend and flatten the notes. This structure of notes (the key) lies within another structure of chords (the progression). Chords are played in a certain, stylized order to create the form of the blues.
The blues is largely based on tonic (I), subdominant (IV), and dominant (V) chords. It's melody line is marked by the use of the lowered third (Eb in our example), lowered fifth (Gb in our example) and dominant seventh (Bb in our example). These are known as the blue notes of the major scale. The bluescats often like to play the flat seventh (Bb in our example) in the chords under that melody.
The term "12-Bar blues" means you play 12 measures (4 beats per measure) of certain bluesy chords in order to complete an AAB phrase. The AAB structure means that the theme from the first line is repeated with some alterations in the second line, and then a concluding theme is introduced in the third line. Not all blues songs follow a standard 12-bar progression, and there are many variations within the 12-bar blues framework.
A generic 12-bar blues looks like this:
I - IV - I - I I - IV - I - I V - IV - I - V A A B
A Basic 12-Bar blues in C looks like this:
C - F - C - C C - F - C - C G - F - C - G A A B
The resolution may signal the end of the song or set up another line. If the song continues, the transition to the next line (or back to 1) is known as the turnaround. A "turnaround" is generally a 1-2 bar fill at the end of the 12-bar progression, which sets us up for our next 12-bars. Turnarounds can be very simple or very complicated.
If you want to play the Hill Country blues, then simplify this structure even more. Keep the phrases one or two chords, keep the melody in one key, forget the turnaround, but keep the beat going. However, as simple as that may sound, it is hard to play it right!