A chord progression is a sequence of chords played in a key. Pick a key, build the chords that belong to it, then put a few of them in an order that leans away from home and comes back. That is the whole job, and a small set of orders has carried most songs ever written. Here is how the chords are built, which progressions reliably work, and how to bend them into something of your own.
Real theory, explained plainly. Works in a piano roll as much as under your fingers, in any key and any style. Nothing here needs a particular instrument.
A chord progression is a sequence of chords played in a key, in an order that leans away from a home chord and returns to it. That movement, leaving home and arriving back, is most of what a progression is for.
Two words underneath it. A chord is a few notes sounded together, most often three, which is called a triad. A key is a home base: a scale of seven notes that a piece mostly draws from, named after the note it treats as home, the tonic. A progression is simply which chords you choose from that key and in what order you play them over time.
The feeling comes from distance. One chord is home, and the others lean away from it by different amounts, some gently, some hard. String a few together and the ear reads the whole thing as setting off and coming back. None of what follows is a rule you must obey; these are the patterns that tend to work, and knowing them makes it easier to hear why a progression of your own does or does not.
Take the scale of your key and stack notes in thirds on each degree, and you get the seven chords that belong to the key. Those are its diatonic chords, the natural palette you write with before you reach for anything from outside.
Start by writing out the scale of your key. In a major key that is the familiar row of seven notes. On each note, build a triad by adding the next two scale notes above it, skipping one each time, so you are stacking thirds. Because the gaps in a major scale are uneven, the seven triads come out in a fixed pattern of qualities that is the same in every major key: major, minor, minor, major, major, minor, diminished, counting from the first degree up to the seventh.
To name them without tying yourself to one key, number the chords by scale degree with Roman
numerals: I, ii, iii, IV, V, vi, vii. Capitals mark the major chords, lowercase the minor ones,
and a small circle marks the diminished chord, so the major key always reads
I ii iii IV V vi vii°. The numerals travel to any key, which is the whole
point of using them. Here is C major worked out in full.
| Degree | Chord | Quality |
|---|---|---|
| I | C | Major |
| ii | Dm | Minor |
| iii | Em | Minor |
| IV | F | Major |
| V | G | Major |
| vi | Am | Minor |
| vii° | B dim | Diminished |
Those seven qualities, major, minor, minor, major, major, minor, diminished, are the same in every major key, because the spacing of a major scale never changes. Learn the pattern once and you can build the chords of any key without memorising each one separately. That is the entire reason for numbering chords instead of only naming them.
You do not need all seven to write. Three do most of the work: I, the home chord, and IV and V, the two chords a fifth on either side of it. These are the primary chords, and between them they can harmonise a great many tunes. Add vi, the minor chord that shares two of its three notes with the home chord and sounds like a softer, sadder version of it, and you have four chords that cover an enormous amount of music.
A handful of orders have carried most songs, because they all set off from the home chord and then pull back to it. Before the list, the pull itself is worth naming, since it is the engine every one of them runs on.
The V chord contains the note just below the home note, and that note leans hard upward into home, so V wants to resolve to I. That resolution, called a cadence, is the strongest sense of arrival in this kind of harmony. Most progressions are built around setting that pull up and then either satisfying it or teasing it. Keep that in mind and the table below stops looking like a list to memorise and starts looking like variations on one idea.
| Progression | In C major | The feeling |
|---|---|---|
| I - V - vi - IV | C - G - Am - F | The modern pop loop. It keeps turning and never quite stops, which is why so many songs sit on it for their whole length. |
| I - vi - IV - V | C - Am - F - G | Warm and nostalgic, the doo-wop turnaround behind a lot of older pop and slow ballads. |
| ii - V - I | Dm - G - C | The strongest short pull toward home. The backbone of jazz, and a clean way to land firmly on any chord you want to arrive at. |
| 12-bar blues (I, IV, V) | C, F and G across 12 bars | A fixed twelve-bar frame built from just the three primary chords, usually with a seventh added to each for the blues edge. |
The blues frame is worth spelling out, since it is a shape rather than a short loop. A common layout is four bars of I, two bars of IV, two bars back on I, then one bar of V, one of IV, and two closing bars of I, with that last bar often turning back to V to start the twelve again. Swap plain triads for seventh chords and you have the sound under a huge amount of blues, rock and early soul.
None of these is a rule, and none is owned by anyone. They are starting points. Change one chord, reorder them, or hold one twice as long, and you have something that is no longer quite any of them, which is exactly how most new progressions get written.
Change the colour of the key, borrow a chord from outside it, or change the rhythm, voicing and inversions, and the same few chords turn into something that sounds like you. The notes barely move; the treatment does most of the work.
Everything above works just as well when home is a minor chord. A minor key is built the same way, stacking thirds on a minor scale, and the pattern of qualities simply comes out darker: from the first degree of a natural minor scale the seven chords run minor, diminished, major, minor, minor, major, major. The one common adjustment is at the fifth chord. In a plain minor key the v is itself minor and pulls home only weakly, so writers often raise its middle note to make it major, which restores the strong lean back to the home chord that a minor key otherwise lacks.
You are not locked to the seven chords of your key. Pulling a chord from the parallel key of the same name, a major key borrowing from its minor or the other way round, adds a fresh colour without leaving home. A major song that borrows its flat sixth and flat seventh, for instance, gets a sudden lift that a lot of anthems and film cues lean on. This is called modal interchange, and it works best kept occasional: one borrowed chord stands out, while a dozen just sounds like you changed key.
The same four chords can sound like two different pieces depending on how you play them, not only which they are. How long you hold each chord, the harmonic rhythm, sets the pace: two beats each feels urgent, a chord held over a bar or two feels calm. How you space the notes, the voicing, sets the size: spread a chord across a wide range and it sounds open and large, pack it tight and it sounds compact. And you need not keep each chord's root as the lowest note. Put a different note of the chord in the bass, which is called an inversion, and the bass line can step smoothly from chord to chord instead of leaping, which is much of what makes a progression flow. Moving between chords with the smallest possible moves is a craft of its own, called voice leading, and it is the natural next thing to learn.
Once the chords are moving, a tune goes on top of them. Our guide to writing a melody covers landing on chord tones so the melody agrees with the progression under it. And for progressions that deliberately avoid arriving home, and float instead of resolving, see chord progressions for ambient and cinematic music.
We built ARGISH to make this part quick. It is a self-playing chord and drone synth: set a key and a mood and it lays down chord progressions that stay in key, voicing them across octaves and holding a drone underneath, all evolving on its own. You hear ideas moving in real time, which is the fastest way to find one worth keeping and steal it into your own track.
It runs free in your browser to try, and installs as AU, VST3, AAX or a standalone app when you want it inside your own sessions.
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