Watch the BB Cool online guitar lesson by Jeff McErlain from 30 Sweet Blues Licks You MUST Know
In this lick, we're primarily outlining the I7 chord of a blues, Bb7 in this case. Bb7 is spelled Bb-D-F-Ab. The first thing we can see is the use of adding in the Db and quickly hammering on to the D natural. This move is exceptionally common and one that should be worked on quite a bit. the b3-3 slur is essential.
The second part of the lick is a little more difficult, as we use a rake across the strings with an up stroke. It's hard to describe in words, so please watch the video carefully. Another player that uses this rake technique quite a bit is Robben Ford, in fact that's where I learned it from. I know he's a huge BB King fan and learned a lot from him. I love being able to trace the roots of many licks and moves to previous guitar players.