An Introduction to the 12 Bar Blues
The most common blues form is the 12-bar blues consisting of the I?IV?V progression. One can also add color the the chord progression by adding “dominant seventh chords,” “quick changes,” or “turnarounds.” The progression below is a blues in the key of G. You will see twelve measures, or bars, containing the following chords: I (G7), IV (C7), and V (D7) chords in the key of G. This would be an example of a “quick change,” because after the first bar of the I chord (G7), the harmony shifts immediately to the IV chord (C7). The last two bars are known as the “turnaround” because chordally, it turns you around to the I chord at the top of the progression.
