Watch the Down 6ths online guitar lesson by Jeff McErlain from Solo Factory: Chicago Blues
This is a great classic turn around! I'm sliding down the interval of the sixth chromatically. I start with an open E on the downbeat of bar 11, it is important to sound this note to keep the turnaround timed correctly. Next I play the interval of the sixth by fretting the D and B on the fifth and third string, I let my second finger flop down to mute the fifth string in between so it doesn't ring out. I fret the B note with my first finger and I also let that flop down to mute the top two strings. I move this down chromatically while strumming triplets to end on the B and G# which are the fifth and third of the E7 chord. To finish it off I hit the V7 chord with the standard B7 fingering you had such a problem playing when your first learned it years ago!