The bassists responsibility in building bass lines is to outline the root movement of the chord progression and project the harmony (as well as connect with the rhythmic foundation of the music) There are three ways to formulate bass lines – using chord tones, scale tones and chromaticism. Typically bass lines are a mixture of all three approaches but it’s a good idea to practice each approach independently. Being accomplished with each method will help you in numerous ways, most importantly you’ll develop the skills to create solid bass lines.

Here are three examples of a walking bass line on a twelve bar blues in F. The first bass line example uses only chord tones, the second uses scale tones and the third uses chromaticism. Download the pdf file and follow along with each example.

12 Bar Blues in F walking Bass lines (pdf)

Chord Tone Blues Bass Line
This bass line uses only chord tones.

Scale Tone Blues Bass Line
This bass line uses scale tones from the mixolydian scales that correspond to each chord change. In this F blues we have F7, Bb7 and C7 chord changes. The F7 chord uses an F mixolydian scale, The Bb7 chord uses a Bb mixolydian scale and the C7 scale uses a C mixolydian scale.

Chromatic Blues Bass Line
This bass line adds chromaticism. Chromaticism must be used judicially or else it can obscure the harmony.