Triads: the three-note chords
A triad is a three-note chord made of a root, a third and a fifth, built by stacking two thirds. There are four kinds: major, minor, diminished and augmented. On C they are C–E–G, C–E♭–G, C–E♭–G♭, C–E–G♯. Tap each one to hear the difference.
Built from stacked thirds
Start on any note, skip one letter, take the next, skip one, take the next. From C that gives C, E, G. Each gap is a third, and a third comes in two sizes: a major third (4 half steps) and a minor third (3 half steps). With two thirds and two sizes there are four combinations, and those are the four triads:
| Triad | Bottom third | Top third | Root to fifth | On C | |
|---|---|---|---|---|---|
| major | major third (4) | minor third (3) | 7 half steps | C E G | |
| minor | minor third (3) | major third (4) | 7 half steps | C E♭ G | |
| diminished | minor third (3) | minor third (3) | 6 half steps | C E♭ G♭ | |
| augmented | major third (4) | major third (4) | 8 half steps | C E G♯ |
Major and minor triads both have a perfect fifth (7 half steps) from root to top, which is why they sound stable. The diminished triad squeezes the fifth down to 6 half steps (a tritone), and the augmented triad stretches it to 8. Those altered fifths are what make them sound restless.
The four triads on the staff
Written on the staff, a root-position triad is three notes stacked on consecutive lines or consecutive spaces, like a snowman. The letters stay the same (C, E, G) for all four; only the sharps and flats change.
- C
major: 1 3 5
bright, stable, settled
- Cm
minor: 1 ♭3 5
darker and softer, still stable
- Cdim
diminished: 1 ♭3 ♭5
tense and unstable, wants to move
- Caug
augmented: 1 3 ♯5
unsettled and stretched, hangs in the air
Inversions
A triad keeps its name no matter which note is on the bottom. With the root lowest it is in root position. Move the root up an octave and the third is lowest: first inversion. Move the third up too and the fifth is lowest: second inversion. Pianists use inversions to move between chords with small hand movements; in chord charts an inversion is written as a slash chord, such as C/E (C with E in the bass).
- Root position
C E G · right hand 1-3-5
- 1st inversion
E G C · right hand 1-2-5
- 2nd inversion
G C E · right hand 1-3-5
The same three shapes work for minor: Cm is C E♭ G, then E♭ G C, then G C E♭.
Triads in a major key
Build a triad on each note of the C major scale, using only notes from the scale, and you get the seven chords of the key. The pattern is the same in every major key: 3 major (I, IV, V), 3 minor (ii, iii, vi) and 1 diminished (vii°). Tap them in order:
Tap a numeral to hear one chord; tap a shape to open it.
Augmented triads do not appear in a major key. They turn up in the harmonic minor scale: in A harmonic minor the chord on the 3rd note is Caug. See the key of C major and the chords of every key.
Triads on guitar and piano
On piano a triad is three fingers, usually 1, 3 and 5 in the right hand. On guitar most chord shapes have five or six strings but still only three different notes; the extra strings double some of them. The open C shape (x32010) plays C E G C E: nothing but C, E and G. Knowing which string holds the third is what lets guitarists change a chord from major to minor.
Guitar chords for beginners · Piano chords for beginners · Ukulele chords for beginners
From triads to seventh chords
Stack one more third on top of a triad and you get a seventh chord. The four common types, on C:
- Cmaj7 (major seventh): C E G B, thirds of 4 + 3 + 4 half steps.
- C7 (dominant seventh): C E G B♭, thirds of 4 + 3 + 3 half steps.
- Cm7 (minor seventh): C E♭ G B♭, thirds of 3 + 4 + 3 half steps.
- Cm7♭5 (half-diminished): C E♭ G♭ B♭, thirds of 3 + 3 + 4 half steps.
In a major key, stacking four scale notes on each degree gives Cmaj7, Dm7, Em7, Fmaj7, G7, Am7 and Bm7♭5.
Every major, minor, diminished and augmented triad
Major triads
Minor triads
Diminished triads
Augmented triads
Related: all chords · intervals · chord progressions · music theory basics
Triad questions
What is a triad in music?
A chord of three notes: a root, a third above it, and a fifth above the root. It is built by stacking two thirds. Almost every chord you play on guitar, piano or ukulele is a triad or a triad with extra notes.
What are the four types of triads?
Major (C E G), minor (C E♭ G), diminished (C E♭ G♭) and augmented (C E G♯), shown here on C. They differ only in the size of the two thirds.
What is the difference between a major and a minor triad?
The middle note. A major triad has a major third (4 half steps) above the root; a minor triad has a minor third (3 half steps). C is C E G and Cm is C E♭ G: only the E moves.
What is a triad inversion?
The same three notes with a different one on the bottom. Root position has the root lowest, first inversion the third, second inversion the fifth. C in first inversion is E G C.
Is a power chord a triad?
No. A power chord has only the root and the fifth, with no third, so it is neither major nor minor. Add the third and it becomes a triad.
Which triads are in a major key?
Three major (I, IV, V), three minor (ii, iii, vi) and one diminished (vii°). In C major: C, Dm, Em, F, G, Am and Bdim.
Every chord on this page is spelled and voiced by the site's theory engine. Updated September 2026.