The blues is very important to guitar players. The blues represents a genre of music, a style of music, and a set of repeating chords common to it. Historically the blues has served as a common meeting point for all players, regardless of style and level. No other style of music uses the same chords in every song like blues does. If you learn what those chords are, you can play blues with anyone.

Twelve Bars

The blues is based on a repeated chord progression that repeats every twelve bars. While no two blues performances will sound the same, the chord progressions and form are always the same. Anyone who knows the twelve-bar blues progressions can sit and play the blues with anyone else.

Because blues is based on a common progression, it's easy to collaborate and play with other blues musicians. It's like an international language of guitar music. You could walk into a blues club anywhere in the world and call “Blue in A,” and the players would know exactly what to do. Even if your best friend likes slow Chicago blues, and you like Texas blues, the form and chords are the same, and you can sit down and jam with your friend. You'll be hard-pressed to find someone who doesn't know the blues progression in at least one key. FIGURE 2-10 shows the twelve-bar blues progression in the key of G.

On chord charts, if the same chord is repeated for a long time, the chord is written only once. You just keep playing that chord until you're told to change.

This pattern repeats over and over again, looping endlessly. FIGURE 2-11 shows a simple twelve-bar blues pattern, again in the key of G; but instead of open chords, a common rhythm pattern is used. This pattern has been used in countless numbers of blues songs.

This rhythm pattern, which is reminiscent of a power chord with an extra note, is an extremely common way to play blues rhythm guitar. Notice how the original progression is on the top staff and the bottom staff contains another way to play these chords. The basic chords for a G blues progression will never change. However, as your chord options grow you will be able to play more colorful voicings. We see in FIGURE 2-10 three different ways to play G blues, but the progression hasn't changed; only the way we play the G, C, and D chords.

Blues Keys

The twelve-bar blues example in FIGURE 2-10 contained the chords G, C, and D. Knowing the names of these chords is extremely important and can help you immensely when you play in the key of G. But what happens if you want to play in the key of A, or B? When you play the blues, the key is always called as part of the title. A fellow player may say, “Let's play blues in A.” So what do you do? How do you know the correct chords for blues in A? Here's where we get into some basic music theory.