Triads
Three-note chords stacked in thirds, and their four types, major, minor, diminished and augmented.
Essential
Content under musical review. It may contain inaccuracies.
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Three-note chords stacked in thirds, and their four types, major, minor, diminished and augmented.
Essential
A triad is a three-note chord built from stacked thirds: a root (1), a third (3) and a fifth (5). Nearly every chord you'll play is a triad or a triad with added notes. The quality of its two thirds decides whether the chord sounds major, minor, diminished or augmented.
The four triads on C. First arpeggiated, then together:
Notice that from major to minor only one note changes: the third.
| Type | Formula | Thirds | On C | Symbol |
|---|---|---|---|---|
| Major | 1 3 5 | major + minor | C E G | C |
| Minor | 1 b3 5 | minor + major | C E♭ G | Cm |
| Diminished | 1 b3 b5 | minor + minor | C E♭ G♭ | Cdim |
| Augmented | 1 3 #5 | major + major | C E G♯ | Caug |
root → C
On the fretboard, the notes of C repeat everywhere. Any combination of them, in any order, is still a C major chord:
String 6, Open: E2 · 3 · Third
Open the chord explorer and switch between major and minor without moving the root. Listen for the note that moves by one fret:
C major C minorStack thirds on every note of the major scale and you get seven triads, the diatonic chords. In C major:
| Degree | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| Chord | C | Dm | Em | F | G | Am | Bdim |
The pattern is the same in every major key: major on I, IV and V; minor on ii, iii and vi; diminished on vii°. With that, you can work out the chords of a song just from its key.
Play triads on just three adjacent strings (for example strings 3, 2 and 1). Each triad has three shapes on that set, depending on which note is lowest. These small voicings are great for comping alongside another guitarist or a keyboard without filling the whole register.
C major arpeggioThe power chord (C5, root and fifth) has no third, so it's neither major nor minor; that's why it suits distorted riffs, where a third would muddy the sound. Suspended chords (Csus2, Csus4) replace the third with a second or a fourth; they aren't built in thirds, although chord symbols treat them like triads.
In tonal harmony the diminished triad usually appears in first inversion, and the augmented triad as the result of a passing tone or in harmonic minor (on the third degree), as Kostka and Payne describe.