Chord Progression Suggester
Choose a key and a common progression pattern, and see the actual chord names for that key — no more translating Roman numerals by hand.
C major
| Degree | I | ii | iii | IV | V | vi | vii° |
|---|---|---|---|---|---|---|---|
| Chord | C | Dm | Em | F | G | Am | Bdim |
Where these progressions come from
Every major key shares the same pattern of chord qualities across its seven scale degrees, and every natural minor key shares a different fixed pattern of its own. That means a progression written in Roman numerals — I–V–vi–IV, for instance — describes the same underlying shape whether you play it in C, G, or any other key; only the actual note names change.
This tool builds the seven diatonic chords of whichever key you choose, then maps a handful of well-worn progressions — the four-chord pop pattern, a jazz turnaround, the ‘50s progression, and a couple of minor-key staples — onto the real chords for that key.
Frequently Asked Questions
What does 'diatonic' mean here?
Diatonic chords are the seven triads built from the notes of a single major or minor scale — the chords that naturally belong to a key. In C major that's C, Dm, Em, F, G, Am, and Bdim; every common progression in this tool is built from a key's own diatonic set.
How are the chord qualities decided?
Each scale degree gets a fixed quality in every major key (major, minor, minor, major, major, minor, diminished for degrees I through vii) and a different fixed pattern in every natural minor key. This comes straight from stacking thirds on each note of the scale — it's the same in every key, just transposed.
What does a Roman numeral like 'I–V–vi–IV' mean?
Each numeral names a scale degree — I is built on the first note of the key, V on the fifth, and so on. Upper-case numerals are major chords and lower-case are minor, so "I–V–vi–IV" reads as "major chord on 1, major chord on 5, minor chord on 6, major chord on 4" — the same shape in any key.
Will a suggested progression definitely fit my melody?
These are the most common, most-reused progressions in popular music, so they're a strong starting point in any key — but no progression is guaranteed to fit a specific melody. Play it against your tune and trust your ear over the suggestion.
Writing aid only. A progression is a starting point, not a guarantee it fits your melody.