Theory
Chords
What is a Chord?
A chord is two or more notes played simultaneously. The most common chords are triads (3 notes) and 7th chords (4 notes). Chords are the building blocks of harmony — they provide the emotional context under a melody.
Triad Types
Major
1 M3 P5
Bright, stable
C E G
Minor
1 m3 P5
Dark, stable
C E♭ G
Diminished
1 m3 d5
Tense, unstable
C E♭ G♭
Augmented
1 M3 A5
Dreamy, unstable
C E G#
7th Chords
Adding a 7th to a triad creates richer, more complex harmony. 7th chords are fundamental in jazz, blues, and contemporary pop.
| Chord | Play |
|---|---|
Major 7 Maj7 | |
Dominant 7 Dom7 | |
Minor 7 Min7 | |
Half-Diminished m7♭5 | |
Diminished 7 dim7 |
Chords in a Major Key
Building a triad on each degree of C major produces a chord with a predictable quality. The V chord naturally extends to a dominant 7th, which strongly wants to resolve back to I.
| Degree | Chord | Quality |
|---|---|---|
| I | C | Major |
| ii | Dm | Minor |
| iii | Em | Minor |
| IV | F | Major |
| V | G | Major |
| vi | Am | Minor |
| vii° | B° | Diminished |