Triads are the basis of everything — the chord structure, the harmony, the note choices you make in a bass line or a solo. I used to think scales were the foundation and I taught them that way for years, but I've come to see that triads are the real organizing principle and that the notes of a scale are just ways to connect the triad notes. Now I teach the scales briefly and get right into triads, because that's what unlocks everything else.
What a triad actually is
A triad is the 1-3-5 of a scale — three notes stacked out of that parent scale that give you the core sound of a chord. There are four flavors you need to know: major, minor, diminished, and augmented. Once you understand that the triad is the 1-3-5, you know what it is technically, you're oriented to that set of notes, and you can start applying them.
You can't really teach triads first — I've tried it, and it doesn't land. Students ask where the triad comes from, and the honest answer is it comes from the scale, which means you need the scale first. So I teach the scale, and then I get right into the importance of triads.
Triads are the foundation — scales just connect them
This is the reframe I want you to sit with. A triad is musical — it's the basis of the chord structure, it's the basis of the harmony. Everything in a bass line comes from it and is centered around it, both in how you navigate rhythmically and in the notes you choose. The notes of the scale are just ways to connect those triad notes together.
That flip changes how you practice. Instead of running scales and hoping a bass line falls out, you're building lines out of 1-3-5 and using the other scale tones to move between them. The triad is the skeleton. The scale is the connective tissue.
7ths, 9ths, 11ths, 13ths are upper-structure chord tones
Once you've got the triad as your core, you can look at 7th chords and extensions — the 9, 11, and 13 — as upper-structure chord tones. From that angle, you can actually look at every note of a scale as a chord tone in one way or another. It's just a question of how you use it. That's a much more useful way to think about note choice than "scale notes vs. non-scale notes." Everything inside the scale can function harmonically. Your job is deciding what goes where.
The practice prescription
Get out your shovel and dig on this exercise with major, minor, diminished, and augmented triads. Mix up string combinations, note combinations, inversions — there's never any traffic on the extra mile. Spend most of your time on major and minor; that's ninety-five percent of it. Diminished is basically minor with a flat 5, so if you really know your minors you're not learning a whole new thing. Augmented rounds it out.
Here's the target:
- Work major and minor triads first — they carry the bulk of the harmonic work you'll ever do.
- Add the diminished triad by flatting the 5 of the minor triad. Don't treat it as a new shape; treat it as a minor variant.
- Add the augmented triad to round out the four flavors.
- Play all four triads and their inversions up and down the neck, in every key.
- Start on any note, any position, any string combination — rhythmically group them however you want.
- The goal is to bust up and down effortlessly, without any hesitation, starting on any note-function number in any key.
Key takeaways
- Triads — the 1-3-5 of a scale — are the basis of chord structure and harmony, and they drive the note choices in every bass line you play.
- The notes of the scale are just ways to connect the triad notes. The triad is the skeleton; the scale is the connective tissue.
- 7ths, 9ths, 11ths, and 13ths are upper-structure chord tones, which means every note in a scale can function as a chord tone depending on how you use it.
- Master major and minor first (that's ninety-five percent of the work), then add diminished (minor with a flat 5) and augmented, in every key, every position, up and down the neck.
Harmony is one of the fundamentals I teach, and triads are where the real harmonic work starts. Once you're sold on why triads matter, the next step is getting them physically under your fingers — see fingering positions for triads on your bass neck for the "how." If you want a structured path through all of this, online bass lessons via Zoom are available.
