Many books and teachers have students focus on scales before teaching you much about chords. In my opinion (and I'm not alone), this is a very backwards approach to teaching and learning bass. I feel it's one of the biggest mistakes in instructional material for bass.
Practicing scales and modes with no understanding of chord tones will lead you to many dead ends in understanding music, the bass, and how to create your own basslines. As a bassist, you need to give a lot of attention to studying chord tones.
What Are Chord Tones?
In case you're unfamiliar or unclear with the term, chord tones are the individual notes that, when played simultaneously, create a chord. Bass players don't usually play several notes at the same time, but basslines are intimately connected to the chord tones as I'll explain below. If this all sounds new to you, you probably want to read or review the bass basics section of this site first.
My Main Point
In this article I really want to drive home one point:
Don’t get too caught up in learning scales and modes before learning about chord tones.
Don’t misunderstand me. Scales are important, too. They’re very important. You need to learn about both to be an effective bassist and musician. You need to learn how scales and chords interact and relate. Just remember that chord tones are primary. Songs revolve around chords and chord progressions. Even melodies, despite having scalar qualities, have a strong connection to chord tones.
The better grasp you have of chord tones, the better you will understand all other note patterns. I wish this wasn't such an oversight in instructional material, but it is. I'd say this issue is one of my prime reasons for creating this website.
An Example of the Importance of Chord Tones
I’ll give you an example of how I think many books and teachers misguide students by only talking of the scales used in basslines rather than the chord tones used in basslines.
One of the first basslines many books and teachers teach is the classic boogie-woogie bassline. (We will fully learn this bassline when we discuss blues bass.) The basic pattern sounds like this:
The boogie-woogie bassline uses a two-bar pattern:
Often this bassline is explained as coming from the C mixolydian scale/mode containing the notes C, D, E, F, G, A, and Bb.
This explanation is not wrong; it’s just a bit incomplete. Sure enough, all the notes of the bassline are contained within the scale. But, the explanation misses the critical point of how the notes of the chord are the heart of the bassline.
This bassline would be played on a C7 chord. The notes of a C7 chord are C, E, G, and Bb. I've highlighted the chord tones in blue.
The only note of the boogie-woogie bassline pattern not in the C7 chord is A. The note A can be explained as coming from the mixolydian scale. The rest of the line, however, purely emphasizes chord tones.
Since the bassist’s role is partly to outline chords, I think this is a large piece of the puzzle to skip especially right at the beginning when you're trying to learn what's important to study. Students excitedly think, "Hey, I need to learn scales to make basslines!" Learning scales won't hurt you, but you need to learn the chord tones first and then how the scales apply to them.
The reason the boogie-woogie bassline has been repeatedly used over the past one hundred years or so and is still being used today is because it successfully outlines the chord tones. That's what makes it a strong, supportive bassline. You will notice the basslines and patterns that get used over and over always have this trait in common. Don't just believe me. You should study, analyze, and discover this in your favorite basslines.
A Common Bass Teaching Approach
As a learning bassist you will encounter a lot of instructional material telling you: "Apply scale X when you see chord Y." What you'll discover when you try it in a bassline is it'll often sound weak and wrong to your ears. The reason why is because some of those scale notes like the 2nd, 4th and 6th aren't supportive of the chord. If your original bassline sounds weak you are probably under-emphasizing the chord tones and overemphasizing scale tones. (Or else your rhythm is off. That's a whole different problem.)
This approach is giving you the right notes, but it's also giving you some notes that require special handling. That's not the way I teach and I hope you work through my lessons and prove it to yourself.
So Why Is It Taught That Way?!
There are a couple of reasons why the scale teaching approach is often used. Firstly, as I pointed out there is enough right about it that people eventually work it out and never think to look at it differently. People then continue to teach it to others the way they learned it.
Next, this approach of teaching scales works fine for most other instruments like guitar and piano. As a result, it trickles down to bass teaching. But, bass is a unique instrument playing a very critical role of supporting the chords. Other instruments won't sound as weak if they don't support the chords as well.
Both chords and scales are essential to learn to become an effective bass player and musician. Effective bass players outline chords well. No matter what path you take, your ear will eventually lead you to defining the chords in your basslines anyway. It’s what sounds right.
I feel it’s important that you not be misguided in your learning efforts. There's no reason to delay your progress and point you in the wrong direction at the start. Focus on chord tones. You’ll have an easier time making sense of music and the bass if you do.