Reaching the top of the Note Choice Pyramid, we arrive at Chromatic Tones. Because of their weak sound, Chromatic Tones create tension in music.
Understanding and balancing tension and resolution in music is essential to being a good, creative musician. You'll see all of the great bass players have mastered the balance of Chord, Scale, and Chromatic Tones in their basslines.
What are Chromatic Tones?
Since there are a total of twelve notes, and most scales contain seven notes, there are usually five Chromatic Tones floating about just waiting to be used for good or bad.
How Bass Players Use Chromatic Tones
Chromatic Tones are connecting notes. They never work alone.
Chromatic Tones and Rhythmic Weight
Since Chromatic Tones are so weak and dissonant (have a harsh sound), they need to land in weak rhythmic places like in-between the beat, or on beats 2 and 4.
Occasionally one might fall in a strong place (beat 1 or 3) when it is surrounded by many other strong Chord Tones, but this is rare.
Connecting Two Strong Notes Chromatically
The most common way to use Chromatic Tones is to fill in gaps between stronger notes.
For example, many basslines use the Root-5-b7-8 pattern. It's very common to fill in the chromatic tone between the flat 7th and the root (or its octave) as in b7-7-8. Listen to Sam Thomas' bassline on Out of Sight by James Brown:
It starts off with 5-b7-7-8 and uses the same idea throughout this Eb blues. You can really feel the constant forward momentum created by that chromatic note in the bassline.
There are many common places to fill between strong notes. One of the most common is connecting the third and fifth of a major chord as in: Root-3-4-#4-5.
Another is between the second and third: 2-b3-3.
And, of course, the minor blues scale already connects the fourth and fifth: 4-b5-5.
Do you see a pattern here? The final note of the phrase is always a really strong chord tone (R, 3, or 5).
Chromatic Approach Notes
As a tension producing sound, Chromatic Tones are great for setting up and leading into another strong note. Chromatic Tones don't have to connect two notes; they can just precede a strong note. This propels you into the strong sound and creates a lot of forward motion. When someone's ear hears this mysterious, not-in-the-scale note, it just knows something else is coming.
Chromaticism is like the Alfred Hitchcock of harmony.
Listen to the bassline by Jerry Jemmott on The Thrill Is Gone by B.B King:
I hear bassists play this bassline incorrectly almost every time. It's a B minor blues. The core of the line is just a root and lower fifth on the strong beats 1 and 3.
Jemmott uses chromatic tones to approach each root and fifth from a half-step below:
A# BB F F#F#. Every so often he'll walk E F F#F#.
It's no wonder Jemmott was one of Jaco's big influences; Jemmott knows how music and the bass work.
[If you're wondering, bassists often misplay it with a whole-step below:
A BB E F#F#. Doesn't that sound disgusting?]
Fingering and Chromatic Lines
Now would be a good time to review playing the chromatic scale. Since it spans across five frets on the bass fretboard, it requires shifting.
Here is the fingering for the Chromatic Scale again:
When you play highly chromatic bass parts, you'll find you need to experiment with the fingering a lot. One fingering may have you shifting constantly, while another requires no shifts. Shifting is often unavoidable.
Who Uses Chromatic Tones?
Most bass players use Chromatic Tones somewhere in their basslines to varying degrees. Of the three types of notes on the pyramid (Chord, Scale, and Chromatic), they are the least used. This is because they don't define the chord or even scale. It's very easy to misplace a Chromatic Tone rhythmically and play a “clam” (a wrong note).
Chromatic Tones are trickier to use. For most players hearing and playing them takes getting used to.
Some bass players only learn to use them in a few places as part of their vocabulary like connecting the b7 to the root mentioned above. And, there's nothing wrong with being conservative with them, either.
Other bassists, like James Jamerson or Jack Bruce with their jazz backgrounds, make extensive use of Chromatic Tones. You'll find players with jazz backgrounds play much more chromatically. Jazz makes extensive use of chromatic notes in walking basslines, melodies, and solos, and that influence carries over.
As you investigate your favorite basslines, you'll see that:
Everyone uses Chord Tones constantly.
Most use Scale Tones quite a bit.
Many use Chromatic Tones but sparingly.
Chromatic Tones are great accent notes. They are used sparingly to connect to and between other strong notes in your bassline. You must be careful to place them in weak rhythmic places such as between the beat or on weaker beats like 2 and 4.
If you really learn to hear and play Chord Tones, adding Chromatic Tones will be a natural extension and addition to them.
Once again, just because you now know how to use Chromatic Tones doesn't mean you should use them everywhere. Listen if it fits the rest of the music and style. Know your audience. Study how the great players used and balanced the notes of The Note Choice Pyramid. As the old saying goes: All of the answers are in your record collection. [Umm, tapes...CDs? MP3s? Streaming? Well, they've been saying it for a long time.]
Head to the exercises and song examples to build a firmer grasp of combining all three types of notes. Be prepared. These exercises and songs are harder than many so far. Take your time to really study them. You get what you put into it.