Four chords, a thousand songs: I V vi IV
One progression that comes back in hundreds of songs, and how to hear it.
Adrian9 minupdated
There is always someone at the campfire who plays half the evening on the same grips, and nobody complains. I took that for laziness until I checked the chords of the songs I wanted to play. The laziness is in the songs, not in that person. Four chords, put in the same order, carry a verse, a chorus and half a repertoire in one afternoon.
A progression is an order of chords that comes back
A progression is a run of chords from one key, repeated through a verse or a chorus. It usually starts on the chord that is home, and returns to it so the ear feels something has closed. Four bars, four chords, then round again, and there is nothing else in it.
On a chord sheet you see letters: C G Am F. Two songs later you see G D Em C and it looks like something new, although it is the same thing. Letters tell you where the fingers go, but they do not tell you what a chord does in the song.
You have probably seen the videos where a band plays thirty hits in a row without changing grips. That is not an editing trick but one progression in one key, and the songs differ in melody, tempo and strumming, not in harmony.
Numbers instead of names: 1 5 6 4
Musicians number the chords of a key from 1 to 7. Capital Roman numerals mean major chords and small ones mean minor, so I V vi IV reads: first, fifth, sixth minor, fourth. In the Guitarmatic exercises the same degrees appear as 1 5 6m 4, and on the song page a switch turns the labels C·D·E into 1·2·3.
Why bother with a second notation when letters are shorter. Because when you learn a chord as a letter, you know it in one key, and when you learn it as a number, you know it in all of them. The number tells you the role: home, tension, shade, breath. That role stays the same when you move the song up to fit your voice.
Why this particular four keeps coming back
The first degree is home, and the fifth pulls towards it harder than anything else, so it is the one that makes tension. The sixth is minor and differs from the first by a single note: C is C, E and G, while Am is A, C and E, so C and E are shared. That is why the sixth sounds like a darker twin of the first, and not like a trip somewhere else. The fourth is the breath: it steps away from home without tension and lets you come back calmly.
Home, tension, shade, breath. Four events a verse needs, in the order the ear expects them. That is where the four comes from, not from fashion.
The same four in five keys
Five keys are easy on a guitar because their chords meet the open grips: C, G, D, A and E. In each of them the same numbers give different letters.
| key | I | V | vi | IV | no barre |
|---|---|---|---|---|---|
| C | C | G | Am | F | no, F |
| G | G | D | Em | C | yes |
| D | D | A | Bm | G | no, Bm |
| A | A | E | F#m | D | no, F#m |
| E | E | B | C#m | A | no, B and C#m |
Start with G, the only row in the table without a single barre. The key of C is within reach today as well: put a capo on the fifth fret and play the shapes G, D, Em, C, and the room will hear C, G, Am and F. Your fingers do G, the ears get C, and it is the same song.
How to hear it before you play it
Level 2 of Ear: progressions holds four progressions, all in C major, so only the order of degrees tells them apart. You answer with numbers, not with names, and this is the point where you stop guessing.
Do not ask yourself whether a progression is happy or sad. That shortcut fails, and the books back away from it themselves: “In My Life” by the Beatles is a sad song in a major key. Ask whether a chord is bright or shaded, and where the progression drops. In I V vi IV the drop onto the shaded chord lands in the third bar, always in the same place, and you will recognise the progression by it faster than by any name.
Relatives: the same four chords, a different start
Move the start by one chord and you get two more progressions out of the same four. I vi IV V (in C: C, Am, F, G) is the ballad classic, called The fifties in our Ear exercise. vi IV I V (Am, F, C, G) opens on the shaded chord, which is why it sounds sadder although the notes are exactly the same.
Worth knowing before someone tells you it is a completely different song. The material is one, what changes is the bar you start counting from. Molly Malone leans on I vi IV V all the way through and nobody hears a ballad in it.
What confused me
For the first month I learnt every song from scratch, as if it had chords of its own. I copied the letters off the chord sheet, drilled them, and started again with the next song. I never noticed I was drilling the same thing for the third time in a new costume.
It changed when I started writing chords down as numbers. Then you can see that G D Em C and C G Am F are one thing, and that a new song is usually an old progression with new words and a new strum. You learn it once and play it in every key.
Do this now
Progression strum, progression I V vi IV, key of C.
The loop keeps going and does not wait for you, so you practise the hard part of this progression: the chord change at the point where the hand wants to stop.
Goal: four times round the loop without stopping the strumming hand.
Ear: progressions, level 2 (Four classics).
Four progressions in one key, answers given as degrees. The ear learns the order here, not the chord names.
Goal: six hits out of the eight questions in a series.
Play this
three songs from the catalogueIn all three the four sits in the harmony, not in the description. Good King Wenceslas runs I V vi IV in G on open grips only, Molly Malone leans on I vi IV V, and The Holly and the Ivy closes on vi IV I V: the same chords, three different starting bars.
» If it is one progression, then all those songs sound the same.
They would, if harmony were the whole song. Play the same four chords once with the Harpagan strum, once as a waltz, once with a single stroke per bar, and you will hear three different pieces built from the same chords. The shortest way to check that is Guitar strums: same loop, different strumming pattern.
Read more
- Beginner Guitar Chords in Theory and PracticeSean Laughton · chapters “Chord Progressions” and “Practice: The Key Of C”You get a full set of progressions for each of the five keys, and the explanation of why the sixth degree sounds like a darker twin of the first.
- Guitar Fretboard MasteryNicolas Carter · chapter “Chord progressions”The author closes this topic with one exercise: you take a single progression and play it in five keys, memorising the sound rather than the grips.
- The Complete Technique, Theory and Scales Compilation for GuitarJoseph Alexander · part one, “The Roman Numeral System”The author explains where the capital and small Roman numerals come from, and why a chord and an interval need separate names.
- The I V vi IV progressionWikipediaYou will find a long list of songs built on this progression, and the story of the “Four Chords” medley that started the jokes about four chords.
- musictheory.net lessonsRicci AdamsThere are free lessons called “Diatonic Triads” and “Roman Numeral Analysis”, and you can click through them without a guitar.