This article is written by Toru Hoshino, a jazz bassist and instructor based in Japan who teaches online lessons to students worldwide. In this article, he explains the actual difference between chord tones and scales.
A student of mine recently watched a walking bass line video I’d sent over, and asked: “why did you use this note here?”
Specifically: in the chord “C△7,” I’d used the note A — why?
The short answer: A works perfectly fine over C△7! Let’s dig into why.
Contents
A Quick Music Theory Refresher
The question, essentially, was: over C△7, aren’t the only usable notes
C (root)
E (3rd)
G (5th)
B (7th)
…so why can other notes be used too?
These four notes are called “chord tones,” and they form the foundation for building a bass line.
But — there are usable notes beyond just the chord tones.
Notes You Can Use Beyond the Chord Tones
As it turns out, the 2nd, 4th, and 6th are also available to use.
In the key of C, specifically, that’s:
D (2nd), F (4th), A (6th)
These notes are called “tensions.”
When you add the tensions (2nd, 4th, 6th) to the chord tones (1st, 3rd, 5th, 7th)…
…you get all seven notes from the 1st through the 7th — in other words, the scale.
So the relationship is:
Chord tones + tensions = scale
The bass line I’d sent my student was built with this “scale” concept in mind — that A wasn’t a random note, it was the 6th, drawn deliberately from the broader scale rather than just the four chord tones.
If that’s piqued your curiosity, I’m genuinely glad.
Grasping the theory is one thing — actually hearing where a tension note fits naturally into your own bass line is exactly the kind of judgment a teacher can sharpen fastest.
Want Personalized Feedback on Your Playing?
This is exactly the kind of thing that’s hard to fix alone — and where having a teacher makes all the difference.
At Line on Bass, I offer an online lesson service where you send me a video of your playing, and I give you specific, detailed feedback — every single day if you want.
Students from around the world are using this to fix exactly these kinds of issues and steadily improve their jazz bass skills.