Part 8 : Why Chords Feel the Way They Do
The Story of Music : A calm walk through roots, scales, partials, and the movement they create.
<Story index
Into the Thicket
Last week we were standing on a grassy green riverbank and life was grand. Today we’re following the footpath into a bit of a thicket - so settle down, take your time, and take it at a comfortable pace. It’s a rewarding stroll if you make it to the end. We’re heading toward the understanding of why chords feel stable, colourful, or full of movement - but before we get there, we need to rebuild the ground we’re standing on.
Rebuilding the Scale
We discovered that you can take any note from the twelve-pitch chromatic scale and declare it the root. And that single choice instantly defines a scale around it, because we’re following a modal pattern - in this case the Ionian mode, the major scale. The root is degree 1, and the next six degrees fall into place through that pattern: the interval steps across those chromatic stepping stones which are 2‑2‑1‑2‑2‑2‑1 intervals/frets. This relationship to the root - the number of stones if you like - matters, because it’s the first clue to why some combinations of notes feel settled and others feel like they want to move.
Rebuilding the Chord Frame
That led us to our first two structural elements of a chord: the root (or 1st degree) and the note that vibrates in sympathy with the root and gives the chord its stability - the fifth degree. Now we can add colour. If degrees 1 and 5 give the chord its identity, the 3rd degree gives it colour - and starts to hint at mood.
Now that frame is rebuilt - root, third, fifth - we’re ready to look at what actually happens when these notes sound together, and why they behave the way they do. Our footpath has arrived at the land of harmony.
Discovery Activity
Before we step fully into harmony, take a quick glance at the discovery activity. It shows how the triads fall out of the scale - the pattern we’re about to explain.
In the downloadable discovery activity you’ll build a triad on each degree of the major scale. Don’t worry about doing it now if you’re driving or sitting on a train — just skim it. You’ll see the pattern that emerges: some chords come out major, some minor, one diminished. That pattern isn’t arbitrary; it’s a direct result of the way our modal pattern sits on the chromatic scale.
Tonic
When you take a root note and combine it with a modal pattern (we used the Ionian), you’ve chosen something from your palette and set the mood for the chords you’re going to build. That’s why we call that root the tonic. It’s not a label for the note; it’s a description of the modal tone you’ve chosen to work in.
Where Colour Meets Movement
Up to now we’ve been talking about colour (what gives a chord its flavour) and movement (why some notes feel stable and others feel like they want to go somewhere). Harmony is simply the point where those two ideas meet. To understand why chords feel the way they do, we need to look at what’s physically happening when notes sound together. The physics are simple; the conclusion is what matters. You don’t need to carry the details with you - just the sense of where they point.
Inside the E Major Chord
Take our E major chord as an example. It’s a triad built from three pitches in the major scale: E, G♯, and B. Each of these notes carries its own pattern of partials - the natural higher frequencies that ride on top of any vibrating string. (Some people call them overtones, but “partials” is the clearer term: they’re just the extra pitches the string produces automatically.)
Harmony is what happens when the partials from different notes interact.
Start with E, the root. When you add B, the fifth degree, you reinforce E - because B contains E as one of its partials. Now B reveals itself as seven intervals distant from E on the chromatic scale - seven frets on your guitar - and it comes from a simple ratio of string length: fretting E at the 7th fret makes the string two‑thirds of its open length. That’s why the fifth feels like the right‑hand post of the doorframe: it’s vibrating as a one‑third fraction of the open E string, and it strengthens the identity of the chord by lining up with the root’s strongest partials. It’s that alignment - physical and immediate - that your ear reads as stability.
Then comes the third degree, G♯, the lintel across the top. G♯ also contains E in its partials, but higher up the stack, so it reinforces the root differently. It adds colour because it brings extra partials that don’t align with E - like the D♯ in its pattern. These near-miss frequencies don’t destabilise the chord, but they do give it colour, give it flavour.
The same is true of B: while it reinforces E, it also contributes its own extra partials - like F♯ - which sit between the strong partials of the root. These extra frequencies from degrees 3 and 5 are part of what gives the chord its character. You don’t need to keep track of each one just know that they sit slightly off the root’s strongest partials.
Reinforcement and Rub
So harmony is the interaction of these stacks of partials: the places where they reinforce each other and the places where they rub. Reinforcement gives stability. Rubbing gives colour.
And now that we have our frame - root, third, fifth - and an understanding of why they sit in harmony, this is where things start to get interesting. Once you understand the frame, you can start to move it. That’s exactly what the discovery activity was showing you: the same frame, stepped through the scale, changing colour and stability as the partials shift. You can visit it again here if you wish: https://dm.ie/chords
Take‑Away
By now you’ve seen that harmony isn’t arbitrary. Once you choose a tonic, the diatonic pattern gives you seven notes, and from those seven notes you can build seven chords using the simple 1–3–5 triad formula. That pattern always produces the same family: major, minor, minor, major, major, minor, diminished.
But more importantly, you’ve learned why those chords feel the way they do. Each degree carries its own pattern of partials, and your ear compares that pattern to the tonic automatically. When the partials line up, you hear stability. When they sit slightly off‑centre, you hear imbalance. And when a degree’s strongest partials sit close to the tonic’s partials without reinforcing them - landing in those high‑sensitivity near‑miss zones - your ear registers tension and a strong sense of movement.
So the movement you hear in music isn’t a rule or a convention - it’s your biology responding to how sound behaves. And the seven chords you’ve just built are the basic set of movements every key gives you. In Part 9, we’ll start to explore how you use that 1–3–5 frame in practice.
”The Story of Music” is a complicated one, but not difficult. Told weekly in this series, it keeps unfolding. To explore more you’re invited to join a conversation in The Story of Music reader’s room.