Chords in Keys
Once you know the notes of a key, you can build the chords that belong to it. Each scale degree becomes the root of a triad by stacking 3ʳᵈs.
Example (C Major):
C–E–G = I
D–F–A = ii
E–G–B = iii
Continue this process from each scale degree to build all seven diatonic chords.
Roman Numerals
Roman numerals indicate both the scale degree and the quality of a chord.
• Uppercase = Major
• Lowercase = Minor
• Lowercase + ° = Augmented and Diminished
Major Key Pattern
I ii ii IV V vi vii°
C Major Cmaj Dmin Emin Fmaj Gmaj Amin Bdim
Chord Quality Major Minor Minor Major Major Minor Diminished
Intervals 1-3-5 2-4-6 3-5-7 4-6-1 5-7-2 6-1-3 7-2-4
Each major key contains seven notes and seven diatonic chords—one built from each scale degree.
Major and minor triads both contain a perfect 5ᵗʰ. Their quality is determined by the 3ʳᵈ.
Example:
C–E–G = C Major
C–E♭–G = C Minor
Minor Keys
Minor keys follow a different Roman numeral pattern.
i ii° III iv v VI VII
C Minor C D E♭ F G A♭ B♭
Chord Quality Minor Diminished Major Minor Minor Major Major
Intervals 1-♭3-5 2-4-♭6 ♭3-5-♭7 4-♭6-1 5-♭7-2 ♭6-1-♭3 ♭7-2-4
Watch the companion video below to learn how to identify the chords in a minor key using the Circle of Fourths.
Once you know the scale degree, you immediately know whether the diatonic chord is major, minor, or diminished.
Relative Keys
Relative major and minor keys contain the same notes and the same chords. They simply begin on different scale degrees.
The relative minor is built on the 6ᵗʰ degree (vi) of the major scale.
Examples:
C Major ↔ A Minor
G Major ↔ E Minor
D Major ↔ B Minor
Because the notes are identical, the chord qualities are also identical—the tonic simply changes.
Chords In Major Keys
| I Major | ii Minor | iii Minor | IV Major | V Major | vi Minor | vii° Dim |
|---|---|---|---|---|---|---|
| C-E-G | D-F-A | E-G-B | F-A-C | G-B-D | A-C-E | B-D-F |
| F-A-C | G-B♭-D | A-C-E | B♭-D-F | C-E-G | D-F-A | E-G-B♭ |
| B♭-D-F | C-E♭-G | D-F-A | E♭-G-B♭ | F-A-C | G-B♭-D | A-C-E♭ |
| E♭-G-B♭ | F-A♭-C | G-B♭-D | A♭-C-E♭ | B♭-D-F | C-E♭-G | D-F-A♭ |
| A♭-C-E♭ | B♭-D♭-F | C-E♭-G | D♭-F-A♭ | E♭-G-B♭ | F-A♭-C | G-B♭-D♭ |
| D♭-F-A♭ | E♭-G♭-B♭ | F-A♭-C | G♭-B♭-D♭ | A♭-C-E♭ | B♭-D♭-F | C-E♭-G♭ |
| G♭-B♭-D♭ | A♭-C♭-E♭ | B♭-D♭-F | C♭-E♭-G♭ | D♭-F-A♭ | E♭-G♭-B♭ | F-A♭-C♭ |
| B-D♯-F♯ | C♯-E-G♯ | D♯-F♯-A♯ | E-G♯-B | F♯-A♯-C♯ | G♯-B-D♯ | A♯-C♯-E |
| E-G♯-B | F♯-A-C♯ | G♯-B-D♯ | A-C♯-E | B-D♯-F♯ | C♯-E-G♯ | D♯-F♯-A |
| A-C♯-E | B-D-F♯ | C♯-E-G♯ | D-F♯-A | E-G♯-B | F♯-A-C♯ | G♯-B-D |
| D-F♯-A | E-G-B | F♯-A-C♯ | G-B-D | A-C♯-E | B-D-F♯ | C♯-E-G |
| G-B-D | A-C-E | B-D-F♯ | C-E-G | D-F♯-A | E-G-B | F♯-A-C |
Chords In Minor Keys
| Im Minor | II° Dim | ♭III Major | IVm Minor | Vm Minor | ♭VI Major | ♭VII Major |
|---|---|---|---|---|---|---|
| C-E♭-G | D-F-A♭ | E♭-G-B♭ | F-A♭-C | G-B♭-D | A♭-C-E♭ | B♭-D-F |
| F-A♭-C | G-B♭-D♭ | A♭-C-E♭ | B♭-D♭-F | C-E♭-G | D♭-F-A♭ | E♭-G-B♭ |
| B♭-D♭-F | C-E♭-G♭ | D♭-F-A♭ | E♭-G♭-B♭ | F-A♭-C | G♭-B♭-D♭ | A♭-C-E♭ |
| E♭-G♭-B♭ | F-A♭-C♭ | G♭-B♭-D♭ | A♭-C♭-E♭ | B♭-D♭-F | C♭-E♭-G♭ | D♭-F-A♭ |
| G♯-B-D♯ | A♯-C♯-E | B-D♯-F♯ | C♯-E-G♯ | D♯-F♯-A♯ | E-G♯-B | F♯-A♯-C♯ |
| C♯-E-G♯ | D♯-F♯-A | E-G♯-B | F♯-A-C♯ | G♯-B-D♯ | A-C♯-E | B-D♯-F♯ |
| F♯-A-C♯ | G♯-B-D | A-C♯-E | B-D-F♯ | C♯-E-G♯ | D-F♯-A | E-G♯-B |
| B-D-F♯ | C♯-E-G | D-F♯-A | E-G-B | F♯-A-C♯ | G-B-D | A-C♯-E |
| E-G-B | F♯-A-C | G-B-D | A-C-E | B-D-F♯ | C-E-G | D-F♯-A |
| A-C-E | B-D-F | C-E-G | D-F-A | E-G-B | F-A-C | G-B-D |
| D-F-A | E-G-B♭ | F-A-C | G-B♭-D | A-C-E | B♭-D-F | C-E-G |
| G-B♭-D | A-C-E♭ | B♭-D-F | C-E♭-G | D-F-A | E♭-G-B♭ | F-A-C |