Harmony
Chord progression
A chord progression is an ordered sequence of chords that forms the harmonic backbone of a piece, written with chord names (C G Am F) or Roman numerals (I-V-vi-IV).
What is a chord progression?
It is the series of chords that supports the melody: the chart you read on a lead sheet or tab. It has a length (often 4 or 8 bars that repeat), a harmonic rhythm (one chord per bar, two per bar...) and a direction: it starts on the tonic, moves away, builds tension and comes back.
The end of each phrase is a cadence, which tells you whether the progression closes or loops around.
Why write chord progressions in Roman numerals?
Because a progression is defined by its degrees, not by its chord names. C G Am F in C major and G D Em C in G major are the same progression: I-V-vi-IV. That is the idea behind Roman numeral analysis.
| Name | Numerals | In C | In G |
|---|---|---|---|
| Pop | I-V-vi-IV | C G Am F | G D Em C |
| 50s | I-vi-IV-V | C Am F G | G Em C D |
| Rock / folk | I-IV-V | C F G | G C D |
| Jazz | ii-V-I | Dm7 G7 Cmaj7 | Am7 D7 Gmaj7 |
| Andalusian | i-♭VII-♭VI-V | Am G F E (in A minor) | Em D C B (in E minor) |
Learn the I-V-vi-IV progression and the ii-V-I first: between them they cover a huge share of pop and jazz.
How to play chord progressions on guitar
Start in G major, where everything fits in open chords: G (320003), Em (022000), C (x32010), D (xx0232). Play I-vi-IV-V with four beats per chord, then two beats: you train your changes and your ear at the same time.
For the 12-bar blues, move to A: A7 (x02020), D7 (xx0212), E7 (020100), in the order A7 A7 A7 A7 / D7 D7 A7 A7 / E7 D7 A7 E7.
To change key without learning new shapes, use a capo: the G shapes at the 2nd fret sound in A major (A F#m D E).
How to write your own chord progression
- Pick a key and start on I.
- Move away with a subdominant chord (IV or ii).
- Build tension with V (or V7).
- Go back to I, or fool the ear with vi.
Then change one thing at a time: a chord swapped for its relative (F becomes Dm), a borrowed chord (Fm), a different chord length. Listen to typical progressions by style in the chord progression library, where each one is given in Roman numerals and ready to transpose.
Key takeaways
- A progression is a sequence of chords that shapes a song: home, away, tension, return.
- Written in Roman numerals, it moves to any key.
- Five to know: I-V-vi-IV, I-vi-IV-V, I-IV-V, ii-V-I, 12-bar blues.
- A capo lets you play the same progression in several keys with the same shapes.
Frequently asked questions
What is the most common chord progression?
In pop it is I-V-vi-IV (C G Am F in C), followed by rotations such as vi-IV-I-V. In rock and folk, I-IV-V dominates; in jazz, it is the ii-V-I.
How many chords does a progression need?
Two are enough: many funk and rock songs vamp on I-IV or i-♭VII (Am G). Three chords (I-IV-V) carry the blues and thousands of songs, and most pop choruses use four.
How do I work out a song's chord progression by ear?
Find the tonic first (the chord that feels like rest), then the bass note of each chord. Then try the diatonic chords of the key: nine times out of ten, every chord comes from that set. Write the result in Roman numerals to remember it.
Related terms
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