Now that we have our guidelines, let’s start plugging in the chords in Fig. 1. These two-note voicings (called “tritones”) are incredibly easy to play and you can navigate this whole progression with two fingers and three frets. For starters, just hit each grip four times per bar. Don’t worry that they’re too simple. Not only are small voicings a great way to back a soloist without getting in his or her way, but starting with these two-note beauties also makes it easy to build a blues tune. That’s crucial to keep things from getting boring or repetitious. There’s incredible economy of motion with these babies—you only need to slide one fret down to go from the A7 to the D7 and one fret up to go from the A7 to the E7. Try it! You’ll like it.
Now let’s up the ante by adding a root note to our chords with the shapes in Fig. 2. It’s the same basic idea, all you need to do is tack an open A onto the I chord, fret a D with your second finger for the IV, and use that exact same grip for the V chord.
Now we’ll spice things up with the voicings in Fig. 3. You might have already played some of these chords by accident because all we’re doing is throwing in some open strings that were just sitting there anyway. That gives us a cool A9 for the I, a dark, clangy D13 for the IV, and a huge sounding E7 for our V. We’re getting hipper and deeper with each 12-bar phrase.
Here’s how you can take this beautifully simple concept even further. Instead of just hitting the chords on the downbeat, slide into each chord from a half-step below. If you were strumming before, try picking the chords—either with your pick or fingers. Just about any picking pattern will work and the D13 in particular will sound amazing. How about bouncing between the low root of each chord and the other notes? It all works and works great. Put on your favorite blues record, find a song in A, and play this over and over (note to SRV fans: Stevie would typically tune his guitar down a half-step). Pretty soon you’ll see how easy it is to apply this concept to any key you want.