How chords are built
A chord is three or more notes played together. Most chords are built in thirds: start on a note, the root, skip a letter for the third, and skip another for the fifth. C, E and G is a C major chord; on the keyboard, it’s every other white key. On the staff, notes a third apart sit on neighbouring lines or neighbouring spaces, so a chord in thirds looks like a stack of three lines or three spaces.
What makes a chord major or minor is the size of those thirds, counted in half steps (from one key to the very next, black or white). A major third is 4 half steps and a minor third is 3:
- Major: a major third, then a minor third (C E G). Bright and settled.
- Minor: a minor third, then a major third (C E♭ G). Darker.
- Diminished: two minor thirds (C E♭ G♭). Tense.
- Augmented: two major thirds (C E G♯). Unresolved.
Add one more third on top and you have a 7th chord: the dominant 7th (C E G B♭), the major 7th (C E G B) and the minor 7th (C E♭ G B♭) are the three you’ll meet most. A sus chord replaces the third with the note next to it, the 2nd or the 4th, so it’s neither major nor minor.
Chord formulas count the notes of the major scale from the root: 3 is the major third, ♭3 is the minor third, ♭7 is a whole step below the octave. Here is every kind on C:
| Chord | Formula | On C | Written |
|---|---|---|---|
| Major | 1 3 5 | C E G | C, CM, Cmaj |
| Minor | 1 ♭3 5 | C E♭ G | Cm, Cmin, C− |
| Diminished | 1 ♭3 ♭5 | C E♭ G♭ | Cdim, C° |
| Augmented | 1 3 ♯5 | C E G♯ | Caug, C+ |
| Dominant 7th | 1 3 5 ♭7 | C E G B♭ | C7, Cdom7 |
| Major 7th | 1 3 5 7 | C E G B | Cmaj7, CM7, CΔ7 |
| Minor 7th | 1 ♭3 5 ♭7 | C E♭ G B♭ | Cm7, Cmin7, C−7 |
| Sus2 | 1 2 5 | C D G | Csus2 |
| Sus4 | 1 4 5 | C F G | Csus4, Csus |
Inversions
A chord keeps its name whichever of its notes is lowest. With the root at the bottom it’s in root position; move the root up an octave and the third is lowest, the 1st inversion; move the third up too and it’s the 2nd inversion (a 7th chord has a 3rd inversion as well, with the 7th lowest). Pianists use inversions to move from chord to chord by small steps, and every chord page shows them all, for each hand.
How the chords are spelt here
A black key has two names, and a chord takes the one that keeps its letters in thirds and reads most simply. So this chart has D♭ major (D♭ F A♭) but C♯ minor (C♯ E G♯), and D♯ diminished rather than E♭ diminished, which would need a double flat. Each page gives the other spelling too.
Learning chords on the piano
Learn the shape under your hand and the shape on the page together. On a chord’s page, play it in every position with the fingering shown, then say the notes as you play. To read chords at sight, practise naming them on the staff with the chord reading quiz, and see them in context in the sight-reading exercises, where left-hand triads and inversions come in one level at a time. The chords of each key are on the scale pages.