Four chords open most Saturdays: C, Am, F and G7. Play enough songs and the same handful of moves keeps coming round, in different keys and at different speeds. Numbers are how those moves get written down. Number the notes of a C major scale one through seven, build a chord on each one, and every chord in the key has an address: C is one, F is four, G is five.
The case carries the rest. Uppercase means major, lowercase means minor, and a small circle means diminished. Every major key runs the same pattern in the same order, so once you have seen it in C you have seen it everywhere: I, ii, iii, IV, V, vi, vii°. Three major chords, three minor, and one diminished that turns up far less often than the other six.
The whole rule
I
Major. Uppercase.
ii
Minor. Lowercase.
vii°
Diminished. With a circle.
The same seven, everywhere
Chords of a key
Read across for a key. Read down for a degree.
| Key | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| C | C | Dm | Em | F | G | Am | B° |
| G | G | Am | Bm | C | D | Em | F♯° |
| F | F | Gm | Am | B♭ | C | Dm | E° |
Letters tell you what to play. Numbers tell you what it is doing, and that difference pays the moment a song moves. I, vi, IV, V is C, Am, F, G in the key of C, and G, Em, C, D in the key of G. Same song, same shape, different chords, and one set of numbers covering both. Read the table across and you have transposed a song without touching a chart.
Three shapes will carry you a long way, and two of them are the same four chords in a different order. Look at the cards and then look at what you already know: C, Am, F and G are the first four chords on the resources page. The G7 you learned is standing in for that G, doing the same job with more pull.
Worth knowing
- The V chord is the one that leans hardest back toward home.
- The vi is the relative minor, sitting inside the wheel.
- Nobody counts out loud. This is for reading, not for playing.
Three that do the work
Progressions
Written in numbers, then in the key of C. Each one can be played, which is quicker than taking my word for it.
I · IV · V
In C: C · F · G
The blues backbone
Twelve bars of these three chords and nothing else is most of early rock and roll, and La Bamba never leaves them at all — the whole song is these three, going round. Learn it once and you can sit in on a song nobody has handed you.
I · vi · IV · V
In C: C · Am · F · G
The doo-wop turn
The fifties sound, and the shape under Stand By Me. It leans on the relative minor in the second bar, which is what gives it the ache.
I · V · vi · IV
In C: C · G · Am · F
The one everything uses
The same four chords in a different order, and the most common progression in popular music since. Let It Be runs on it, and so does half of what came after.
One more thing the numbers give you
Somebody calls one, four, five in F and the whole room knows what to play without a chart: F, B♭ and C. Read that row off the table above.
Next
The circle of fifths
Where the IV and the V come from, why neighbouring keys sound related, and how to move a song into a key you can sing.