How to Play the 12 Bar Blues by Jody Worrell is a free online video guitar lesson teaching one of the basic fundamentals of blues. You'll learn how to play a 12 Bar Blues in the key of E. We'll first cover the chords that make up this progression (E7, A7, B7). Next you'll learn the order and length to play each of the chords. After you've got the rhyhm down you can spice things up by adding a turnaround lick over the last two measures of the progression.