Watch the Off the One online guitar lesson by David Santos from 50 Bass Grooves You MUST Know
The form of this tune is A B A.
For letter A we use the D minor pentatonic scale or blues scale, including a low minor third which is a blue note against the dominant 7th chord of the moment. We leave a hole or rest on the downbeat of one.
Letter B goes to the 5 chord. The bass line in letter B utilizes a minor third as a blue note against the dominant 7th chord of the moment as well. Work on your durations and rhythms throughout the piece. Understand blue notes and how they sound. Swing the bridge in a subtle way.