Diatonic triads
Build the seven triads of a major key and know their qualities.
You know the scale of a key. Now we build the chords of that key, one on every note of the scale.
Seven chords from seven notes
Diatonic means “using only the notes of the key”. Build a triad on each degree of the major scale by stacking 3rds with scale notes only, and you get the seven diatonic triads, the diatonic chords of the key. In C major:
| Degree | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Chord | C | Dm | Em | F | G | Am | B° |
| Quality | major | minor | minor | major | major | minor | diminished |
The pattern major – minor – minor – major – major – minor – diminished is the same in every major key. In G major the chords are G, Am, Bm, C, D, Em, F♯°.
| Key | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| C | C | Dm | Em | F | G | Am | B° |
| D♭ | D♭ | E♭m | Fm | G♭ | A♭ | B♭m | C° |
| D | D | Em | F♯m | G | A | Bm | C♯° |
| E♭ | E♭ | Fm | Gm | A♭ | B♭ | Cm | D° |
| E | E | F♯m | G♯m | A | B | C♯m | D♯° |
| F | F | Gm | Am | B♭ | C | Dm | E° |
| F♯ | F♯ | G♯m | A♯m | B | C♯ | D♯m | E♯° |
| G | G | Am | Bm | C | D | Em | F♯° |
| A♭ | A♭ | B♭m | Cm | D♭ | E♭ | Fm | G° |
| A | A | Bm | C♯m | D | E | F♯m | G♯° |
| B♭ | B♭ | Cm | Dm | E♭ | F | Gm | A° |
| B | B | C♯m | D♯m | E | F♯ | G♯m | A♯° |
The chord family
Most songs in a major key use mainly these chords, the chord family of the key, and most of all the three major ones (degrees 1, 4 and 5) and the three minor ones (2, 3 and 6).
Every scale note belongs to three diatonic chords: once as a root, once as a 3rd and once as a 5th. In C major, the note C is in C, F and Am. This is how chords are chosen under a melody (lesson 9.6).
The Key Chords tool shows the chords of every major key, with bass boxes.
In C major, play the root, 3rd and 5th of each diatonic chord in order, from C to B°, saying its name and quality.
New terms
Tools
- Key Chords: The chords of every major and minor key, chosen on the circle of fifths, with bass boxes and common progressions.