Below is a 4-step guide to creating walking bass lines. It is as straightforward an explanation as I've read. Link to page here "Creating a walking bass line is one of the more elusive art forms in the bass world, but if you understand how to put it together, step by step (pun intended), it won't seem so frightening. The formula for a successful walking bass line is simple: Beat One: Determine the chord tonality (major, minor, dominant, or half-diminished) and play the root of that chord. Beat Two: Play any chord tone of the chord, or any note in the scale related to that chord. Beat Three: Play any chord tone or scale tone of the chord. Yep same as Step 2, but try to pick a different note. Beat Four: Play a leading tone to the next root. A leading tone leads from one chord to the next. The leading tone prepares the listeners ear for the sound of the new chord. The most important point to understand about a leading tone is that it aims for the following chords root. For example, if youre going from a C chord to an F chord, your leading tone leads to F (never mind the C)."