How to build a triad
A triad is the simplest full chord in music — just three notes stacked in a neat pattern. Learn the one stacking rule and four short formulas, and you can build any chord starting from any note. Here's the step-by-step.
A triad is a three-note chord built by stacking thirds. Almost all the harmony you hear in pop, rock, folk, and classical music starts here. Once you can build a triad on any note, you understand the bones of how chords work.
Learn it by ear
Triads click when you hear them, not just spell them. Our free game plays notes, you match them back — train your ear on each triad's sound in minutes. Keep this guide open and jump in.
1. The basic shape: root, third, fifth
Every triad has three parts:
- Root — the bottom note, which names the chord.
- Third — the note a third (skip one letter) above the root.
- Fifth — the note a fifth (skip two letters) above the root.
Counting by letters from C, you skip every other one: C – (skip D) – E – (skip F) – G. So a triad on C uses the notes C, E, G. That "every other letter" stacking is the heart of triad-building.
2. Step-by-step on any note
- Choose your root. Say, G.
- Add the third — skip one letter: G → (skip A) → B.
- Add the fifth — skip the next letter: B → (skip C) → D.
- Check the quality with half steps (next section) and add any sharps or flats needed.
That gives you G–B–D, a G major triad. The letter-skipping always gives the right note names; the half-step formulas below fine-tune the sound.
3. The four triad formulas (in half steps)
Measure each chord tone in half steps above the root. A half step is the smallest jump on a keyboard — one key to the next.
- Major = 0 – 4 – 7 (major third + perfect fifth) — bright, happy. C–E–G.
- Minor = 0 – 3 – 7 (minor third + perfect fifth) — dark, sad. C–E♭–G.
- Diminished = 0 – 3 – 6 (minor third + flat fifth) — tense, unstable. C–E♭–G♭.
- Augmented = 0 – 4 – 8 (major third + sharp fifth) — dreamy, unsettled. C–E–G♯.
Notice the pattern: major and minor differ by the third; major and augmented differ by the fifth; minor and diminished differ by the fifth. Small changes, big mood swings.
Echo
Call-and-response pitch memory: hear a triad's notes and sing them back. The fastest way to connect each formula to the sound it makes.
4. Triads on the staff: the snowman
Written out, a triad in its basic position is the classic snowman shape: three notes stacked a third apart, so they're all on lines or all in spaces, root on the bottom. Any accidentals (sharps or flats) decide whether that snowman is major, minor, diminished, or augmented.
The notes E, G, B stacked on the bottom three lines make an E-rooted triad — root, third, fifth, all on lines.
5. Common mistakes to avoid
- Skipping a letter wrong. A triad always uses every-other letter (C–E–G), never two adjacent ones.
- Forgetting the key. If you're in a key with sharps or flats, apply them to your chord tones.
- Mixing up third vs. fifth changes. The third controls major/minor; the fifth controls diminished/augmented.
6. A quick practice plan
- Spell major triads on every white-key root until it's automatic.
- Convert each to minor by lowering the third — then to diminished and augmented.
- Sing the three notes aloud so you hear, not just calculate, each chord.
- Train your ear daily in short bursts to match formulas to sounds.
Play the arcade
No sign-up, no install. Train your ear on triads and intervals, one quick round at a time.
Frequently asked questions
What is a triad?
A triad is a three-note chord built by stacking thirds: a root, a third above it, and a fifth above the root. Major, minor, diminished, and augmented triads all share this root-third-fifth structure.
How do you build a triad?
Pick a root note, then add the note a third above it and the note a fifth above it. Adjust the third and fifth with the right number of half steps to choose major (0–4–7), minor (0–3–7), diminished (0–3–6), or augmented (0–4–8).
What are the four types of triads?
Major (bright), minor (dark), diminished (tense and unstable), and augmented (dreamy and unsettled). They differ only in the size of the third and fifth above the root.
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