Triads: Major, Minor, Diminished, Augmented
Here you'll learn to build any three-note chord by stacking intervals, to recognize the four main families, major, minor, diminished and augmented, and to put suspended chords and power chords to work.
A chord is several notes played together. With what you know about intervals, you already have everything you need to build one. The principle fits in one sentence: you stack thirds. Start from a note, add a third above it, then another third above the second note, and you get a three-note chord, which is also called a triad.
Every other note of the scale
First, listen to these four chords, all built the same way in the C major scale. You start on a note, skip the next one, take the one after that, skip another, and take the next.
You heard it: each chord sounds like a single block. Each of its three notes has a name. The starting note, the one that gives the chord its name, is the root. The middle note, a third above, is the third. The top note, a fifth above the root, is the fifth. On the grid, a chord built from the scale always has the same shape: three notes in a staircase, taking every other highlighted row.
Major and minor: only one note changes
What sets chords apart is the size of their two thirds. A major chord stacks a major third, four half steps, then a minor third, three half steps. C major, written simply as C, contains C, E and G.
A minor chord does the opposite: the minor third at the bottom, the major third on top. C minor, written Cm, contains C, E♭ and G. Compare it with the previous figure: only the middle note has moved, down by a half step.
In both cases, the fifth stays perfect, seven half steps above the root. It's the third, and only the third, that decides whether the chord sounds bright or dark, exactly as in the major and minor scales. On the grid, remember the shapes by counting the rows from one note to the next: four then three for a major chord, three then four for a minor chord.
Diminished and augmented: the two unstable chords
With two thirds, there are two combinations left. If you stack two minor thirds, you get a diminished chord, written C° or Cdim, which contains C, E♭ and G♭. Its fifth has only six half steps: it's a tritone. If you stack two major thirds, you get an augmented chord, written C+ or Caug, which contains C, E and G♯. Its fifth has eight half steps: it's an augmented fifth.
Listen to all four in a row. Major and minor are stable. The diminished chord sounds tight and uneasy, because of the tritone it contains. The augmented chord sounds like it's floating, as if suspended: its three notes are equally spaced, four half steps each, and your ear isn't quite sure which one is the root anymore. These two chords are mostly used as a passage between two stable chords, or as a tension effect in a film-score mood or a dark loop.
| Chord | Symbol | Stacked thirds | Half steps from the root | On C |
|---|---|---|---|---|
| Major | C | major then minor | 0, 4, 7 | C E G |
| Minor | Cm | minor then major | 0, 3, 7 | C E♭ G |
| Diminished | C° or Cdim | minor then minor | 0, 3, 6 | C E♭ G♭ |
| Augmented | C+ or Caug | major then major | 0, 4, 8 | C E G♯ |
Suspended chords: no third
Since the third decides the color, what happens if you take it out? You replace it with a neighboring note, and you get a suspended chord. In a sus4 chord, the third is replaced by the perfect fourth: Csus4 contains C, F and G. In a sus2 chord, it's replaced by the major second: Csus2 contains C, D and G. Listen to each of them followed by the major chord.
These chords are neither major nor minor, and that's the whole point. The sus4 sounds like it's waiting: its fourth wants to drop a half step to the major third, which gives a small resolution that's used a lot at the end of a phrase. The sus2 sounds open and airy, and it can hold for a long time without asking for anything. In electronic music, you often hear them in pads and pluck chords, precisely because they avoid choosing between bright and dark.
The power chord, or fifth chord
Let's strip things down even further: keep only the root and the fifth, possibly with the root doubled an octave up. That's the power chord, as guitarists call it, also known as a fifth chord, and it's written with a 5: C5 contains C and G. With no third, it has neither a major nor a minor color, only weight.
Being so bare makes it very solid when the sound is distorted or very rich in harmonics: a distorted third quickly gets dirty, while a fifth stays clean. You hear it in rock and metal, of course, but also in many distorted basses and leads in electronic music, and in the low end in general, for the reasons we saw in the previous lesson.
Now take a few minutes to build these chords yourself, on several different roots. Change the chord type without changing the root, and listen to what moves.
| Note | Role | Interval | Semitones |
|---|---|---|---|
| C | Root | starting point | 0 |
| E | Third | major third | 4 |
| G | Fifth | perfect fifth | 7 |
In root position, the root is the lowest note: the most stable form of the chord.
Build these four chords by counting half steps from the root: D minor (Dm), E major (E), B diminished (B°) and F sus4 (Fsus4). Write down their notes, then place them in your software, one chord per bar, and listen.
You can now build a chord on any note. The next lesson shows you which chords naturally belong to a key, and how to number them.