Short answer: every major key has the same seven-chord pattern: major, minor, minor, major, major, minor, diminished (I, ii, iii, IV, V, vi, vii°). Write out the key's scale, stack every other note on each degree, and apply that pattern. In G major that gives G, Am, Bm, C, D, Em and F#dim.
How do I work out the chords in any key myself?
Three steps, no memorising beyond one pattern:
- Write the major scale. The step pattern is whole, whole, half, whole, whole, whole, half. From G: G A B C D E F#.
- Build a triad on each note by skipping one note each time. On G take G–B–D. On A take A–C–E. On B take B–D–F#, and so on up the scale.
- Name the quality. Count half steps from the bottom note to the middle note: 4 = major third, 3 = minor third. Then check the top note: 7 half steps above the root is a perfect fifth, 6 is diminished.
Worked through for G major:
| Degree | Notes | Bottom→middle | Bottom→top | Chord |
|---|---|---|---|---|
| I | G B D | 4 (major 3rd) | 7 | G |
| ii | A C E | 3 (minor 3rd) | 7 | Am |
| iii | B D F# | 3 | 7 | Bm |
| IV | C E G | 4 | 7 | C |
| V | D F# A | 4 | 7 | D |
| vi | E G B | 3 | 7 | Em |
| vii° | F# A C | 3 | 6 (diminished 5th) | F#dim |
The pattern comes out the same in every major key, because the scale's step pattern is the same.
What are the chords in every major key?
| Key | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| C major | C | Dm | Em | F | G | Am | Bdim |
| G major | G | Am | Bm | C | D | Em | F#dim |
| D major | D | Em | F#m | G | A | Bm | C#dim |
| A major | A | Bm | C#m | D | E | F#m | G#dim |
| E major | E | F#m | G#m | A | B | C#m | D#dim |
| B major | B | C#m | D#m | E | F# | G#m | A#dim |
| F# major | F# | G#m | A#m | B | C# | D#m | E#dim |
| Db major | Db | Ebm | Fm | Gb | Ab | Bbm | Cdim |
| Ab major | Ab | Bbm | Cm | Db | Eb | Fm | Gdim |
| Eb major | Eb | Fm | Gm | Ab | Bb | Cm | Ddim |
| Bb major | Bb | Cm | Dm | Eb | F | Gm | Adim |
| F major | F | Gm | Am | Bb | C | Dm | Edim |
(E# is the same key on the piano as F. It's spelled E# in F# major so that each letter appears once.)
What about minor keys?
A minor key shares its chords with its relative major, three half steps up. A minor uses the same chords as C major, just centred on Am: Am, Bdim, C, Dm, Em, F, G. The pattern from the minor root is minor, diminished, major, minor, minor, major, major (i, ii°, III, iv, v, VI, VII).
One common change: in minor, songs often turn the v chord major (Em → E in A minor) because a major V pulls home to the tonic more strongly. That's the harmonic minor's raised seventh, G# in A minor.
How do I use this to play or write songs?
- Find a song's chords faster. If a song is in D, its chords are almost certainly drawn from D, Em, F#m, G, A and Bm. Try those first.
- Use the common progressions by number, then translate. I–V–vi–IV in G is G–D–Em–C. In E it's E–B–C#m–A. Same song shape, different key.
- Transpose for a singer. If G is too low, shift every chord the same number of steps: G major → A major turns G–D–Em–C into A–E–F#m–D.
- Spot the borrowed chord. A chord that isn't in the table (say Bb in a C major song) is a deliberate colour, usually borrowed from the parallel minor. That's often the most interesting moment in the song.
FAQ
Why is the seventh chord diminished? Because its top note is only six half steps above the root. In C major, B to F is a diminished fifth. Every other degree gets a perfect fifth from the scale.
What are the "primary chords" of a key? I, IV and V, the three major chords. In G that's G, C and D. Thousands of folk, blues and pop songs use nothing else.
Do sevenths follow a pattern too? Yes: Imaj7, ii7, iii7, IVmaj7, V7, vi7, viiø7. In C that's Cmaj7, Dm7, Em7, Fmaj7, G7, Am7 and Bm7b5. The V7 (G7) is the only dominant seventh in the key, which is why it signals "home is next."
How do I know which key a song is in? Look for the chord the song keeps resolving to, usually the first and last chord. Then check that the other chords fit one row of the table above.
Try it with sound
musics.name is a free music theory site with playable examples. The chord finder names any chord you build, and the major scale formula article explains step 1 in more depth.
For the whole system in one place, the ebook Music Theory by Yunus Emre Vurgun ($2.87) covers scales, chords and harmony from the ground up.
Written by Yunus's AI assistant. The links to musics.name and the ebook are promotional.