How Chords Are Built
Every chord is a specific stack of intervals above a root note. Learn those stacks and you can build, name, and analyze any chord — and understand why each one sounds the way it does.
Chords Are Stacked Intervals
A chord is three or more notes sounding simultaneously. Each note is a specific interval above the root. Change any interval by one semitone and you get a completely different chord with a different emotional character.
Most chords are built in thirds — stacking every other scale degree. A major triad stacks a major 3rd, then a minor 3rd on top. That specific spacing is what makes it major.
Chord Explorer
Root Note
Triads
Suspended
7th Chords
Extended
Bright, happy, resolved — the default "cheerful" chord. The foundation of Western harmony.
The Four Triad Qualities
All four basic triads share the root and the perfect 5th — what changes is just the middle note. That one interval determines the entire emotional character.
Adding Colour: Triads → 7th Chords → Extensions
Stack another 3rd on top of a triad and you get a 7th chord. Stack another 3rd on that and you get a 9th chord. Each layer adds harmonic colour and complexity.
Simple and powerful. The backbone of pop, rock, and classical harmony.
Adds sophistication. Blues uses dom7, jazz uses maj7 and min7 constantly.
Maximum colour. Jazz and neo-soul territory — rich, lush, complex.
Chords From a Key
Build a chord on each scale degree — only using notes in the key — and you get the diatonic chords.
Key
Click any chord to explore it in the Chord Explorer above. In any major key: I, IV, V = major · ii, iii, vi = minor · vii = diminished
Decoding Chord Symbols
| Symbol | Means |
|---|---|
| C | C major triad |
| Cm | C minor triad |
| C7 | C dominant 7th |
| Cmaj7 | C major 7th |
| Cm7 | C minor 7th |
| Cdim | C diminished triad |
| Cdim7 | C fully-diminished 7th |
| Cm7♭5 | C half-diminished |
| Caug | C augmented triad |
| Csus4 | C suspended 4th |
| Csus2 | C suspended 2nd |
| Cadd9 | C add 9 (no 7th) |
| C5 | C power chord (5th chord) |
Naming shortcut
No suffix = major triad. Lowercase m = minor triad. A bare number (7, 9…) = dominant quality (♭7). The word maj before a number means the 7th is major (natural), not flatted. So C7 = dominant 7th (♭7) and Cmaj7 = major 7th (natural 7).
See every chord shape on guitar
The Chord Visualizer has fingering diagrams, audio playback, and staff notation for all 14 chord types across all 12 keys.