Harmony
Chord progressions: how songs move
A chord progression is the order chords arrive in, and it is what makes a song feel like it is going somewhere. A handful of these orders carry most of recorded music — which is why so many songs feel familiar the first time you hear them.
This page sits above the chord library, where every chord type has its own page.
I–IV–V
Three chords, built on the first, fourth and fifth notes of the key. Folk, country, rock and roll, and half of everything on the radio.
ii–V–I
The engine of jazz. Tension gathers on the two, sharpens on the five and resolves home — the strongest arrival in tonal music.
12-bar blues
A fixed twelve-bar frame on I, IV and V. Not a song but a form: thousands of blues and early rock records share it.
What a chord progression is
A chord is several notes at once; a progression is the order they come in and how long each one lasts. That order is what carries the feeling of movement: the same three chords in a different sequence make a different song, and the same sequence under a different melody still sounds like the same ground.
Progressions are written in roman numerals rather than letters, because the numeral describes the position in the key, not a fixed pitch. I–IV–V is C–F–G in C major and G–C–D in G major — the same relationship, moved. That is why a chart written once works in all twelve keys, and why musicians say «two five one» instead of naming chords.
The progressions worth knowing first
Four sequences cover an enormous amount of repertoire. I–IV–V is the backbone of folk, blues and rock. I–V–vi–IV — the so-called four-chord progression — carries a remarkable share of pop from the last fifty years. ii–V–I is the standard jazz cadence, usually moving through several keys in one tune. And the twelve-bar blues is a fixed form rather than a loose sequence: three chords laid over twelve bars in a set pattern.
Two more earn their place quickly. vi–IV–I–V is the same four chords as the pop progression started from the minor, which is why it sounds darker without changing a single note. And I–vi–IV–V, the fifties progression, gives doo-wop its sound. Learn these six and most songs you pick up will be a variation on something you already know.
Where the chords come from
Every key supplies its own set of chords, built by stacking thirds on each scale degree. In a major key that gives three major chords on I, IV and V, three minor ones on ii, iii and vi, and a diminished chord on vii. Those seven are the chords that sound at home; anything else is borrowed, and borrowing is what makes a moment stand out.
This is why progressions written in numerals transfer between keys, and why a chart says «in C major» rather than listing chords. Once you know the seven chords of the key you are in, a progression stops being something to memorise and becomes a choice among a small set — which is the point at which writing your own starts to be possible.
Why some progressions sound sad
Mood comes less from the chords themselves than from where the progression starts and where it lands. Beginning on a minor chord — vi–IV–I–V rather than I–V–vi–IV — colours the whole loop, even though the chords are identical. Ending away from the tonic leaves a question open; ending on it closes the door.
A few specific moves have reliable effects. The minor four in a major key, borrowed from the parallel minor, is the classic ache under a final chorus. A descending bass line under held harmony gives the sense of something sinking. And a progression that never quite reaches the tonic keeps a song restless from beginning to end.
Using progressions in your own songs
Start from a loop of four chords and change one thing at a time: the order, the rhythm of the changes, the bass note under a chord. Most memorable progressions are small variations on common ones, not inventions — swapping the last chord of a familiar loop is often the whole idea behind a song that sounds new.
The practical move is to hear it rather than analyse it. Put a progression under a melody you already have and the wrong chords announce themselves immediately; put a melody over a progression and the phrase tends to write itself towards the arrival point. Both directions work, and both are faster than choosing chords on paper.
Where to go next
Every progression is built from chords that share a key — the circle of fifths shows which ones those are. To hear a progression instead of reading it, open the progression generator and pick a key.
Common questions
What is a chord progression?
The order chords arrive in and how long each lasts. It is written in roman numerals — I–IV–V, ii–V–I — because the numerals describe positions in the key, so the same progression works in all twelve keys.
What are the most common chord progressions?
I–IV–V, I–V–vi–IV, ii–V–I, the twelve-bar blues, vi–IV–I–V and I–vi–IV–V. Between them they cover an enormous share of folk, pop, jazz, blues and rock.
What is the 2-5-1 progression?
The minor chord on the second degree, the dominant seventh on the fifth, then home to the first. It is the standard jazz cadence, and a tune usually passes through it in several keys.
What is the 12-bar blues progression?
A fixed twelve-bar form using only I, IV and V: four bars of I, two of IV, two of I, then V, IV and two bars of I. Thousands of blues and early rock records share this frame.
How do I write my own chord progression?
Take a familiar four-chord loop and change one element — the order, the timing, or the bass note. Then play it under a melody: wrong chords are obvious by ear long before they look wrong on paper.
Hear a progression before you commit to it
Open the studio, drop a progression in and let it play with bass and melody underneath. Choosing chords by ear takes minutes; choosing them on paper takes an evening.