One of the main goals of chord substitution is to create more interesting bass line movement to compliment a song’s melody. An understanding of logical bass line movement can help you make better chord substitution choices. Below are examples of five types of bass line movements that have been repeatedly used to create hits songs.
Chromatic bass lines ascend or descend in half steps. The first example is the opening A section progression to Ain’t Misbehavin’ (Standard – 1937) shown below that is an example of an ascending chromatic bass line. The second example is the opening verse progression to Walk Away Renee (Left Banke – 1966) shown below that an example of a descending chromatic bass line.
|Cmaj7 / C#o7 / ||Dm7 / D#o7 /|| C/E / E7#5 / || F6 / Fm6 /
|C / / / ||G/B / / /|| Bb / / / || F/A / / /
||Abo7 / / /||C/G / / /
Cyclical bass lines follow circle of fifth movement descending by fifths (three and a half whole steps) or by fourths (two and a half whole steps). The first example shown below is the bridge to I Got Rhythm (Standard – 1937) that moves counterclockwise around the circle in descending fifths. The second example is the chord progression to Hey Joe (Leaves – 1966) that moves clockwise around the circle in descending fourths.
|E7 / / / ||/ / / /|| A7 / / / ||/ / / /
||D7 / / / ||/ / / /|| G7 / / / ||/ / / /
|Ab / Eb / ||Bb / F /|| C / / / ||/ / / /
Diatonic bass lines ascend or descend in scale steps. The first example is the main verse progression to Like A Rolling Stone (Bob Dylan – 1965) shown below that an example of an ascending diatonic bass line. The second example is the opening verse progression to Mr. Bojangles (Nitty Gritty Dirt Band – 1971) shown below that is an example of a descending diatonic bass line.
|C / Dm / ||Em / F /|| G / / / ||/ / / /
|C / / ||C/B / /|| Am / / ||C/G / /
Pedal points sustain the same bass note through a series of chord changes. The main verse progression to Billie Jean (Michael Jackson – 1983) shown below is an example of a tonic pedal point.
|Am / Bm /A / ||C/A / Bm/A /
Tritone bass lines move up three whole steps then resolve down a half step. Bars nine to twelve of the A Section to Here’s That Rainy Day (Standard - 1949) shown below includes two examples of bass lines that move by three whole steps, then have a downward half step resolution.
|Fm7 / / / ||Fm7 / B9 Bb9|| Ebmaj7 / A9 / ||Abmaj7 / / /
In the following lessons, you will look at a dozen must-know chord substitution techniques for any songwriter, performer, or arranger. (Excerpt from Chord Progressions For Songwriters) Click below for the best in free Bass Line lessons available on the web.