Watch the Counterpoint online guitar lesson by Jeff McErlain from 50 Eclectic Blues Licks You MUST Know
As you can see by looking through this course, turnarounds are pretty important. I was first really introduced to them by Eric Clapton on the Live Cream records. Of course he didn't invent them, it's where I first became aware of them.
Check out the live version of Sleepy Time Time on Live Cream. He nails the turnaround almost every time and it sounds awesome. He changes up the phrasing a fair amount which is cool and a great tune for us to look at. Plus his tone is KILLING!