Which chords belong to a key, and how to find a song's key
Why do some chords just sound right together? Most songs pull their chords from one small family. Every major key has the same seven-chord pattern, so once you learn it, you know it in all twelve keys.
By Todd Fisher. The diagrams and note names here come from the same code as our tools, and they're tested. See something wrong? Let me know.
Where the chords come from
Take a major scale. In C, that's C D E F G A B. To build a chord on any note, stack every other note from the scale on top of it. Start on C and you get C E G, a C major chord. Start on D and you get D F A, a D minor chord. Keep walking up the scale and you end up with seven chords, all made from notes in the key.
| Numeral | Chord | Notes |
|---|---|---|
| I | C | C E G |
| ii | Dm | D F A |
| iii | Em | E G B |
| IV | F | F A C |
| V | G | G B D |
| vi | Am | A C E |
| vii° | Bdim | B D F |
Hear it in any key
Pick a key and tap a chord to hear it. Then play one of the progressions, change the key, and play it again. Higher or lower, it's still the same song.
Play a progression
The pattern in every major key
The chord types always come in the same order, whatever the key:
major, minor, minor, major, major, minor, diminished
Roman numerals show this at a glance. Capitals are major, lowercase are minor, and ° means diminished. You won't use the diminished chord much, so really you're working with six.
| Key | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| C | C | Dm | Em | F | G | Am | Bdim |
| G | G | Am | Bm | C | D | Em | F#dim |
| D | D | Em | F#m | G | A | Bm | C#dim |
| A | A | Bm | C#m | D | E | F#m | G#dim |
| E | E | F#m | G#m | A | B | C#m | D#dim |
| F | F | Gm | Am | Bb | C | Dm | Edim |
| Bb | Bb | Cm | Dm | Eb | F | Gm | Adim |
| Eb | Eb | Fm | Gm | Ab | Bb | Cm | Ddim |
| Ab | Ab | Bbm | Cm | Db | Eb | Fm | Gdim |
Chords in the most common keys
Chords in the key of C
C, Dm, Em, F, G, Am, Bdim
Of the six main chords, only F usually needs a barre on guitar. On piano, you stay on the white keys.
With a capo: fret 3 with A shapes, fret 5 with G shapes.
Chords in the key of G
G, Am, Bm, C, D, Em, F#dim
Guitarists love this key. G, C, D and Em are all open shapes, and only Bm usually needs a barre.
With a capo: fret 3 with E shapes, fret 5 with D shapes, fret 7 with C shapes.
Chords in the key of D
D, Em, F#m, G, A, Bm, C#dim
D, G, A and Em are open on guitar. Expect to barre F#m and Bm.
With a capo: fret 2 with C shapes, fret 5 with A shapes, fret 7 with G shapes.
Chords in the key of A
A, Bm, C#m, D, E, F#m, G#dim
A, D and E are the classic three open chords here. Bm, C#m and F#m usually mean barres.
With a capo: fret 2 with G shapes, fret 5 with E shapes, fret 7 with D shapes.
Chords in the key of E
E, F#m, G#m, A, B, C#m, D#dim
Great for guitar riffs, thanks to that open low E. The catch is that F#m, G#m, B and C#m usually need barres.
With a capo: fret 2 with D shapes, fret 4 with C shapes, fret 7 with A shapes.
Chords in the key of F
F, Gm, Am, Bb, C, Dm, Edim
Singers often like F more than guitarists do, since F, Bb and Gm usually need barres. A capo helps.
With a capo: fret 1 with E shapes, fret 3 with D shapes, fret 5 with C shapes.
Chords in the key of A minor
Am, Bdim, C, Dm, Em, F, G
Same chords as C major, but Am is home. Am, C, Dm, Em and G are all open shapes on guitar.
Chords in the key of E minor
Em, F#dim, G, Am, Bm, C, D
Same chords as G major, but Em is home. It sits really comfortably on guitar.
Minor keys
Every major key shares its notes with a minor key, called its relative minor, which starts on the 6th note of the scale. A minor has the same chords as C major, just starting from Am. The numerals change because home has moved.
| Key | i | ii° | III | iv | v | VI | VII |
|---|---|---|---|---|---|---|---|
| A minor | Am | Bdim | C | Dm | Em | F | G |
| E minor | Em | F#dim | G | Am | Bm | C | D |
| D minor | Dm | Edim | F | Gm | Am | Bb | C |
| G minor | Gm | Adim | Bb | Cm | Dm | Eb | F |
| C minor | Cm | Ddim | Eb | Fm | Gm | Ab | Bb |
One thing to watch for: the v chord often gets played as a major or 7th chord. In A minor, you'll hear E or E7 where the table says Em.
One progression, any key
Since the pattern never changes, a progression is really just a set of numbers. Here are a few you'll recognize, in C and in G:
| Numerals | In C | In G |
|---|---|---|
| I - IV - V | C - F - G | G - C - D |
| I - V - vi - IV | C - G - Am - F | G - D - Em - C |
| vi - IV - I - V | Am - F - C - G | Em - C - G - D |
| ii - V - I | Dm - G - C | Am - D - G |
What key is this song in? Find it from the chords
No single clue is always right, so use a few together.
- Listen for home. Which chord feels finished? Stop the song on different chords. The one that feels like you could stop there is probably the key.
- Look at the last chord. Songs often end at home, and often start there too. It's a strong hint, though not a guarantee.
- Match the chords to the chart. Find the row that holds most of the song's chords. If a song uses G, C, D and Em, the G row has them all.
- Look for a 7th chord that resolves. When D7 moves to G, you're very likely in the key of G.
Worked example
Say a chart has Am, F, C and G. C major and A minor both contain all four, so the chords alone won't settle it. You have to listen. If the song feels at home on C, it's in C major and the progression is vi - IV - I - V. If it comes to rest on Am, it's in A minor.
What you can do with this
- Learn songs faster. Once you know the key, you can often guess the next chord.
- Write your own. Pick any chords from one row and they'll sit together. Try starting somewhere other than I.
- Change key. Keep the numbers and swap the row, or let the transposer handle a whole song.
- Find notes to solo with. The notes of the key fit its chords. The Scale Explorer shows them on your instrument.
Frequently asked questions
Can a song use chords outside its key?
Sure, and lots do. An outside chord adds color. The key just tells you where most of the chords come from and where the song feels at home.
What's the difference between a song in C major and one in A minor?
They use the same seven notes and the same chords. What changes is home base. If the song comes to rest on Am, it's probably in A minor.
Why is the V chord in a minor key often major?
The natural minor scale gives you a minor v, but songwriters often raise one note to make it major, because a major V pulls harder back home. In A minor, that means E or E7 instead of Em.
What are the Roman numerals for?
They name a chord by its place in the key instead of by its letter. I-V-vi-IV is the same progression in any key, so you can change key and keep the song intact.