How do I get the same progression back later?

Write down the key, the length and the seed. Those three inputs are the whole recipe: typing them in again rebuilds exactly the same chords, in the same order, on any device. Shuffle draws a new seed between 0 and 999,999 and prints it, so a progression you liked is never lost to the next press of a button.

Are all the chords in the key?

Yes. Each chord is a triad stacked from the seven notes of the key you chose, so every note of every chord is a note of that scale. There are no borrowed chords, no secondary dominants and no key changes. The seven chords of the key are listed under the tool, so you can see exactly which chords the generator is drawing from.

What do I and vi mean next to the chords?

They are Roman numerals, the way musicians name a chord by its place in the key rather than by its letter. Capitals are major chords, lower case are minor, and the small ring marks a diminished chord. I vi IV V in C major is C, Am, F, G, and the same numerals in G major are G, Em, C, D: that is why changing the key with the seed untouched transposes the progression instead of replacing it.

Can I hear the progression?

Yes. Play walks the whole progression, sounding each chord for 1.1 seconds, and clicking a single chord plays just that one. The notes are plain sine tones generated in the browser at A4 = 440 Hz equal temperament, so there is nothing to download and no instrument sample. Stopping, hiding the tab or leaving the page silences it at once.

Which keys can I choose?

All 15 major keys and all 15 minor keys that spell with single sharps or flats, from C major round to Cb major and from A minor round to Ab minor. A key such as D# major is refused with a note that Eb major has the same pitches, because writing D# major honestly needs a double sharp. Minor keys are natural minor, so the seventh degree is not raised and every chord stays inside the key signature.

How many chords can one progression have?

From 2 to 16 chords in one go. A template holds two to four degrees, and a longer progression continues one chord at a time through the follow table written into the tool, which never repeats a chord straight back to back. Asking for more than 16 is refused with the limit named rather than quietly shortened.

Can I copy the progression into my own notes?

Copy puts the whole thing on the clipboard as plain text: the key, the length and the seed, then the chord names over their Roman numerals, then the notes of each chord and the same notes as MIDI numbers. The columns line up, so a chord and its numeral stay together wherever you paste them.

Is anything uploaded or saved anywhere?

No. The chords are worked out in your browser and nothing is sent anywhere. The key, the length and the seed are kept on this device so the tool opens where you left it, and the Start over button above the tool forgets them.

Chord Progression Generator

Pick a key, a length and a seed, and the page writes a progression whose every chord belongs to that key. Each chord is shown with its name, its Roman numeral, its three notes and its MIDI numbers, and a click on any chord plays it as plain sine tones. The seed is printed beside the progression rather than hidden: the same key, length and seed always rebuild the same chords, so the one you liked comes back by typing its number back in instead of pressing generate until it reappears. The progressions come from degree templates written into the tool, such as I vi IV V, extended through an authored follow table when you ask for more chords than a template holds, so nothing here is lifted from an existing song.

C major4 chordsSeed 512

scale C D E F G A B

Key

Length

Numerals

I vi IV V

Seed

4 chords in C major, from the I vi IV V template, seed 512. Play sounds each chord for 1.1 seconds as plain sine tones.

C major, 4 chordsseed 512
C Am F G I vi IV V
A minor, 4 chordsthe same seed, the minor templates
Am F C G i VI III VII
G major, 4 chordsthe same seed, the same numerals
G Em C D I vi IV V

The seven chords of C major

Every chord above is one of these seven. The templates leave the diminished degree out, so it is here rather than in a progression.

Degree	Chord	Notes	MIDI	Root
I	C	C E G	60 64 67	261.6 Hz
ii	Dm	D F A	62 65 69	293.7 Hz
iii	Em	E G B	64 67 71	329.6 Hz
IV	F	F A C	65 69 72	349.2 Hz
V	G	G B D	67 71 74	392.0 Hz
vi	Am	A C E	69 72 76	440.0 Hz
vii°	Bdim	B D F	71 74 77	493.9 Hz

How a progression is built. The seed, the mode and the length pick one of the degree templates written into this tool, such as I vi IV V, and a longer progression carries on one degree at a time through an authored follow table. The tonic then decides only what those degrees are called, so seed 512 in C major and in G major is the same set of numerals in two keys. Nothing is quoted from a song, and no chord comes from outside the key.

2 to 16 chords in one go, seeds from 0 to 999,999, generated in this browser with nothing uploaded and no account. The key, the length and the seed are kept on this device alone, and the Start over button above the tool forgets them.

Accuracy. Every chord is diatonic to the key you choose, built from the degree templates written into this page. The same key, length and seed always give the same progression, and nothing here is taken from any existing song.

Common questions

How do I get the same progression back later?: Write down the key, the length and the seed. Those three inputs are the whole recipe: typing them in again rebuilds exactly the same chords, in the same order, on any device. Shuffle draws a new seed between 0 and 999,999 and prints it, so a progression you liked is never lost to the next press of a button.
Are all the chords in the key?: Yes. Each chord is a triad stacked from the seven notes of the key you chose, so every note of every chord is a note of that scale. There are no borrowed chords, no secondary dominants and no key changes. The seven chords of the key are listed under the tool, so you can see exactly which chords the generator is drawing from.
What do I and vi mean next to the chords?: They are Roman numerals, the way musicians name a chord by its place in the key rather than by its letter. Capitals are major chords, lower case are minor, and the small ring marks a diminished chord. I vi IV V in C major is C, Am, F, G, and the same numerals in G major are G, Em, C, D: that is why changing the key with the seed untouched transposes the progression instead of replacing it.
Can I hear the progression?: Yes. Play walks the whole progression, sounding each chord for 1.1 seconds, and clicking a single chord plays just that one. The notes are plain sine tones generated in the browser at A4 = 440 Hz equal temperament, so there is nothing to download and no instrument sample. Stopping, hiding the tab or leaving the page silences it at once.
Which keys can I choose?: All 15 major keys and all 15 minor keys that spell with single sharps or flats, from C major round to Cb major and from A minor round to Ab minor. A key such as D# major is refused with a note that Eb major has the same pitches, because writing D# major honestly needs a double sharp. Minor keys are natural minor, so the seventh degree is not raised and every chord stays inside the key signature.
How many chords can one progression have?: From 2 to 16 chords in one go. A template holds two to four degrees, and a longer progression continues one chord at a time through the follow table written into the tool, which never repeats a chord straight back to back. Asking for more than 16 is refused with the limit named rather than quietly shortened.
Can I copy the progression into my own notes?: Copy puts the whole thing on the clipboard as plain text: the key, the length and the seed, then the chord names over their Roman numerals, then the notes of each chord and the same notes as MIDI numbers. The columns line up, so a chord and its numeral stay together wherever you paste them.
Is anything uploaded or saved anywhere?: No. The chords are worked out in your browser and nothing is sent anywhere. The key, the length and the seed are kept on this device so the tool opens where you left it, and the Start over button above the tool forgets them.

Every chord is diatonic to the key you choose, built from the degree templates written into this page. The same key, length and seed always give the same progression, and nothing here is taken from any existing song.