Chord Progression Generator (common pop & classic progressions in any key)

Understanding the chord progression generator — concept and principle

This tool writes out common chord progressions in any key: the chord names, the Roman numerals and the three notes of each chord. Songwriters use it to start a song, students use it to hear how one pattern sounds in different keys, and players use it to get a progression ready for a capo or a singer's range.

Numerals become chords: with the default inputs the result is C – G – Am – F (loop it bar by bar).

How it is calculated

Each progression is stored as Roman numerals: scale degrees of the key, upper case for major chords and lower case for minor ones (° for diminished).
The root of each chord is found from the tonic by counting letters up the scale, then adding ♯ or ♭ to land the right number of semitones above the tonic. In a major key: ii = 2, iii = 4, IV = 5, V = 7, vi = 9 semitones. In a minor key: III = 3, VI = 8, VII = 10.
A 3rd (4 semitones for major, 3 for minor and diminished) and a 5th (7, or 6 for diminished) are stacked on each root.

The principle

Roman numerals describe a chord's role in the key, not its letter name, so a progression written in numerals works in every key. The tonic chord (I) feels like home. The dominant (V) pulls back towards it. Predominant chords such as IV and ii lead to V. Four-chord loops such as I–V–vi–IV (often called the singer/songwriter schema) and I–vi–IV–V (the doo-wop schema) combine these roles in a cycle, which is why so many songs share them. Changing the key moves every chord by the same amount, so the progression keeps its character while the pitch changes.

Worked example

Default inputs: key C, progression I – V – vi – IV.

I: C is the tonic; C major = C E G.
V: five letters up the scale is G, 7 semitones above C; G major = G B D.
vi: A, 9 semitones above C; minor, so a minor 3rd: A minor = A C E.
IV: F, 5 semitones above C; F major = F A C.
Result: C – G – Am – F, numerals I – V – vi – IV, key C major.

How to read the result

Play the chords as a loop, usually one per bar, and repeat. The same numerals in another key give the same feel at a different pitch, for example G – D – Em – C in G major. Try rotating the loop (starting on vi gives Am – F – C – G) or changing one chord to make the pattern your own.

Common mistakes

Using a major chord where the numeral is lower case, for example A instead of Am for vi in C.
Forgetting that minor-key progressions use a different set of degrees.
Choosing a key that sits outside the singer's range.
Worrying that a common progression is copying; chord progressions are shared building blocks.

Keep in mind: The generator gives plain triads in common patterns. Real arrangements add sevenths, inversions and rhythm, and minor keys often raise the 7th degree to make a major V, which these simple loops do not show.

Frequently asked questions

What is the most common pop chord progression?

I–V–vi–IV (C–G–Am–F in C) and its rotation vi–IV–I–V are found in a very large number of pop songs.

What key should I choose?

One that suits the singer's range, or one with easy shapes on your instrument such as G, C, D or E on guitar.

Sources: M. Gotham et al., Open Music Theory, 2nd ed. (VIVA Pressbooks), "Four-chord schemas" (B. Hughes & M. Lavengood) · S. Kostka, D. Payne & B. Almén, Tonal Harmony, 8th ed. (McGraw-Hill, 2018)

Checked 9 Nov 2026. Open Music Theory, 2nd ed. (M. Gotham et al., open textbook, VIVA Pressbooks), “Four-chord schemas” (B. Hughes & M. Lavengood): doo-wop I–vi–IV–V (and I–vi–ii–V), singer/songwriter I–V–vi–IV with its rotations and minor form i–VI–III–VII, hopscotch IV–V–vi–I with minor forms VI–VII–i–III and VI–V–i–III. I–IV–V–I and I–ii–V–I are the standard tonic–predominant–dominant–tonic phrase.

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