The 12 bar Blues is a pattern of chords which repeats every 12 bars. It is the most common progression in Blues music, and is used extensively in Rock and Jazz as well. In this lesson there are two examples of 12 bar blues in the key of C. (For more on keys, see Progressive Keyboard Technique ). Both progressions make use of the chords C, F and G in the right hand part. In the next example, the chords are played as arpeggios.