Watch the Blues Study in D 4 online guitar lesson by Tim Sparks from Post-Modern Fingerstyle Blues

The bass line's feel is created by playing 6/8 against 4/4; that is, you create the familiar pulse of a 6/8 even though the rhythm is counted in steady 4's. Getting the feel right is the central to playing the part, so get familiar with the bass exercise shown, including all the hammers and pulls, before trying to marry the bass to the melody.