Building chords
A chord is three notes, not six fingers. We will see where they come from, which of them decides happy or sad, and what all those letters in the name are telling you.
Until now you have played chords because that is how somebody taught you to put your fingers down. In this lesson you find out what is actually inside them — and after that, chord names stop looking like a secret code.
Here is the first surprise: an ordinary chord is made of three pitches and no more. When you strum across six strings, you are simply sounding those same three pitches at several different heights.
It goes by the name triad. Three notes, and almost everything you play in your first two years is built out of them.
Where do the three come from? From the scale we built in the previous lesson, by a single rule: start on any note, then skip its neighbor and take the next one.
In C major, starting on C: C, skip D, take E, skip F, take G. That leaves us with C-E-G, which is a C major chord.
In the language of degrees those are degrees one, three and five, which is why they are called the root, the third and the fifth. The names sound scholarly, and what hides behind them is very simple indeed:
If three notes are enough, why does an open chord use six strings?
Because doubling is not waste, it is thickness. The same pitch at two different heights sounds fuller and wider than it does on its own, in the same way that a choir sounds different from one singer holding a single note.
Look at an E minor chord: six strings, and only three different pitches in there — E, G and B. Some of them turn up twice, and one of them turns up three times. That is why it sounds so full next to a pair of strings.
It is also why you can drop a string without wrecking anything. When you learned Asus2 and skipped the sixth string, you did not lose the chord — you removed one copy of a pitch that was already in there.
Here is the prettiest demonstration on the guitar, and it costs one finger:
Those two chords differ by one note. In E minor, the distance from the root to the third is three half steps. In E major it is four — a half step higher, and that is the whole story.
Play them back to back a few times over. One half step, and the mood of the chord flips completely. Music theory has no better demonstration of how little it takes to change everything.
On the guitar that difference is exactly the finger you add at the first fret of the third string. Once you have seen it, you will not be able to stop seeing it.
If the third sets the mood, what happens when you take it out?
You get a power chord: root and fifth, nothing else. It is not major and it is not minor — it simply refuses to answer the question.
Which is precisely why it rules rock: with no third it sounds strong and neutral, it does not collide with the melody, and it survives distortion that would turn a full chord to mud. Two strings, endless songs. We go into it properly in the lesson on power chords.
It is worth stopping on the question everybody skips: why do those three particular pitches melt into a single sound, when three neighbors do not?
The answer sits in physics. Every note you hear is not one sound but a stack of faint sounds above it, laid out in a fixed order. The fifth of the chord lives high in the root's stack, and the third is up there too — so when you play them together, the ear hears something it has already heard being reinforced, not a collision.
That is also why the fifth sounds emptier and steadier than the third: it sits closer to the bottom of the stack, which is another way of saying that it is more obvious.
You do not need to hold any of this in mind in order to play. But it changes the way you think about chords — they are not an arbitrary combination somebody settled on, they are a combination the ear was prepared for in advance.
Now we carry that same skipping rule one step further: after one, three and five comes seven. A fourth note, and the whole character shifts.
All three are four-note chords, and all three sound completely unalike:
Notice that this “unfinished” chord is not a flaw. The tension is its job, and that is exactly the subject of the next lesson.
If a chord is only three notes, why does E minor have seventeen versions in the dictionary?
Because their order and their height matter. Those three pitches can be laid out in dozens of ways: E-G-B, or G-B-E, or B-E-G, each of them at different heights and with different doublings. The result is the same chord as far as the name goes, and a completely different character as far as the sound goes.
That is called voicing, and it is the tool that separates somebody who plays chords from somebody who accompanies. A low, tightly packed version sounds heavy; a high, spread-out version sounds airy; the very same chord, two different jobs inside one song.
There is nothing to chase here at this stage. Just notice, as you flip between the positions on a chord card, that you are not moving between different chords — you are moving between arrangements of the same three notes.
One more thing worth knowing, because it explains the odd names you will meet in tabs.
The lowest pitch in a chord — the one the ear takes as the foundation — affects the feel more than all the rest put together. Usually it is the root, and then everything feels settled and plain. But you can put a different note at the bottom, and then you get a name with a slash in it, C/E for instance.
The result is a chord that sounds less “finished”, which makes it excellent in the middle of a progression that is still going somewhere. In songs this is what creates the sense of a bass line walking gradually downwards while the chords above it change — an old trick, and one of the loveliest there is.
Once you know the structure, the name stops being arbitrary. It is simply telling you what is inside:
| Symbol | What it means | Example |
|---|---|---|
| no suffix | a major triad | C |
| m | the third dropped by a half step | Am |
| 5 | no third at all, a power chord | E5 |
| 7 | a seventh added, tension created | G7 |
| maj7 | a higher seventh, a dreamy sound | Cmaj7 |
| m7 | minor with a seventh, softened | Em7 |
| sus2, sus4 | the third swapped for a neighbor, no mood | Asus2 |
| add9 | color added without taking anything out | Cadd9 |
Now look again at the Asus2 you learned in the first lesson of your life. The suffix says “the third has been replaced”, and that is exactly why it sounds open and undecided. There was never any magic in it — there was a formula.
The only way this part genuinely lands is through your ears.
The chord dictionary — open the sound and see which notes it is built from
Take one chord and hear it beside its neighbors: major, minor, seventh, suspended. Ten minutes of that and you will start picking them out in songs, which is roughly the moment theory stops being homework.
| What happens | Why | What to do |
|---|---|---|
| “I cannot hear the difference between major and minor” | The ear needs the two side by side | Alternate E and E minor, ten times over |
| Mixing up m7 and maj7 | The names look alike, the sounds do not | m7 broods, maj7 floats. Listen to them in a row |
| Trying to pick out three notes inside a full chord | Too hard as a first step | Pick it string by string, slowly, and listen to the lowest pitch |
| Forgetting what the third even is | An abstract term with nothing to hold on to | It is the finger that separates E from E minor |
In the next lesson we take these chords and see how they organize into families — and why certain progressions turn up in so very many songs.