A chord is a group of three or more notes sounded together. Music students first learn the four triads (major, minor, augmented and diminished) and then the most important seventh chords: dominant seventh, leading-tone seventh (half-diminished) and diminished seventh. Each page below shows how the chord is built, its intervals and its symbols.
Types of chords
Triads
Triads
Major, minor, augmented and diminished: the four three-note chords.
Major Triad
Major 3rd + perfect 5th. The most stable chord, with a bright sound (C–E–G).
Minor Triad
Minor 3rd + perfect 5th. A dark or melancholy sound (C–E♭–G).
Augmented Triad
Major 3rd + augmented 5th. Tense and unstable (C–E–G♯).
Diminished Triad
Minor 3rd + diminished 5th. Tension that wants to resolve (C–E♭–G♭).
Seventh chords
Seventh Chords
The five types (dominant, major, minor, half-diminished and diminished), their structure and symbols.
Dominant Seventh
The chord of the authentic cadence V7–I. Tension and resolution.
Major Seventh
Major triad + major 7th (Cmaj7). A bright sound, on scale degrees I and IV.
Minor Seventh
Minor triad + minor 7th (Cm7). A soft sound, on degrees ii, iii and vi.
Leading-Tone Seventh
The half-diminished chord: a diminished triad with a minor 7th. It resolves to the tonic.
Diminished Seventh
The most tense of them all: four symmetrical notes stacked in minor thirds.
Intervals and symbols for each chord type
The table below sums up the intervals and the usual symbols of the chords studied in this section. Lead-sheet chord symbols (letter names) are used in jazz and popular music; Roman numerals are used in harmonic analysis.
To practice them as a game, try Bowling, where you recognize written triads, and Pool, where you build them yourself.
| Chord | Intervals above the root | Lead-sheet symbol | Roman numeral (in C) |
|---|---|---|---|
| Major triad | Major 3rd + perfect 5th | C | I |
| Minor triad | Minor 3rd + perfect 5th | Cm / C- | i |
| Augmented triad | Major 3rd + augmented 5th | C+ / Caug | III+ (in A minor) |
| Diminished triad | Minor 3rd + diminished 5th | C° / Cdim | vii° |
| Dominant seventh | Major 3rd + perfect 5th + minor 7th | G7 | V7 |
| Leading-tone seventh (half-diminished, viiø7) | Minor 3rd + diminished 5th + minor 7th | Bø / Bm7♭5 | viiø7 |
| Diminished seventh (vii°7) | Minor 3rd + diminished 5th + diminished 7th | G♯° / G♯dim7 | vii°7 |
Frequently Asked Questions
What is a musical chord?
A chord is a group of three or more notes sounded at the same time. The most basic type is the triad, made of three notes stacked in thirds.
How many types of triads are there?
There are four: major, minor, augmented and diminished. They differ in the size of the third (major or minor) and of the fifth (perfect, augmented or diminished).
What is a seventh chord?
A seventh chord adds a fourth note to a triad, a seventh above the root. The most important ones are the dominant seventh (V7), the leading-tone (half-diminished) seventh and the diminished seventh.
What is a chord inversion?
A chord is in root position when its lowest note is the root. In first inversion the lowest note is the third; in second inversion it is the fifth (and in third inversion of a seventh chord, the seventh). Inversions change the color of the chord without changing its notes.
What is the harmonic function of a chord?
Harmonic function describes the role of a chord within a key: tonic (I), subdominant (IV) or dominant (V). The V7–I authentic cadence is the strongest move in tonal harmony, because the dominant builds tension that is released when it reaches the tonic.