Play a Blues Shuffle
Let’s begin with a simple shuffle pattern that is chorded with only two fingers. Begin by playing the open fifth string along with the fourth string fretted with your index finger at the second fret. You’ll notice that these are the lowest two notes of an open A or A7 chord. This pared-down version of an A chord contains only the root and fifth and can be referred to as an A5. When strumming this chord, be careful to hit only the fourth and fifth strings. If you’re having difficulty avoiding the higher strings, try flattening the index finger of your left hand slightly in order to dampen the second and third strings. The next step is to fret the fourth string at the fourth fret with your ring finger while playing the fifth string open. Play this pattern with a steady eighth-note rhythm, as in Example 1.
Excerpted from Acoustic Blues Guitar Essentials