How to Use Chromatic Tones to Play the Bass Guitar
When you play a bass line, you’re not limited to the notes in the main modes; you can supplement them with notes outside the mode. The extra notes that fall within the box — the chromatic tones — are the most convenient notes for supplementing your modes.
Chromatic tones normally refer to any sequence of notes moving in half steps, either up or down, one fret at a time. For bass lines, however, chromatic tones refer to the notes outside the regular mode. These notes are a half step away from a scale tone. You play chromatic tones in passing to the stronger scale tones.
Chromatic tones within the box
Look at this bass line in a major tonality using a chromatic tone. You don’t need to shift your left hand to reach these chromatic notes, because they’re in the box. You can use these notes as quick links to one of the chord tones (root, 3, 5, 7). Listen to a chromatic tone in a major bass line.
Here, you see a bass line in a minor tonality using a chromatic tone. You can also listen to this chromatic tone.
The chromatic tones add a little tension to the bass lines — tension that’s promptly released on the next note.
You can also see these bass lines played.
Chromatic tones outside the box
Most songs, have a shape, or form. In other words, they have a certain way the melody moves up and down and repeats ideas, or phrases.
Tunes are arranged into measures and phrases; in the vast majority of cases, four measures equal a phrase. Just as horn players and singers pause at regular intervals to breathe, a tune also generally pauses between musical phrases.
As the bassist, you’re responsible for indicating the form of a tune to the other players. The notes you play tend to set up (lead to) the beginning of each new phrase, and you often can use chromatic tones to accomplish this.
You usually use chromatic tones that are inside the box to lead from one strong scale tone to the next, but you also may want to use chromatic tones that fall outside the box (which means you have to shift your left hand to reach them). Use them to lead to the chord tones (root, 3, 5, 7), which identify the tonality.
As you experiment with chromatic tones, make sure your overall tonality doesn’t get obscured. You still want your sound to be recognizable as major or minor.
Here, you see a bass line in a major tonality using a chromatic tone outside the box to lead to a strong chord tone (in this case, the 3 of the chord).
The chromatic tones serve to make the groove more interesting. You reach outside the scale temporarily to give the music tension, but then you resolve it (lead to a chord tone).