The chords
Every chord links to its full reference page — notes, keyboard diagram, audio, fingering, and inversions.
Which key is it in?
A progression's key is the one whose scale contains all of its chords, and the Roman numerals below are each chord's job in that key. When several keys qualify, the ear usually decides by where the music comes to rest.
| Key | Roman numerals | Named pattern |
|---|---|---|
| D major | ii – V – I | The ii–V–I |
| B minor | iv – ♭VII – ♭III | Not a named pattern |
| C♭ minor | iv – ♭VII – ♭III | Not a named pattern |
Why The ii–V–I works
The engine of jazz harmony: predominant to dominant to home. The ii sets up the V, the V pulls hard to the I — the smoothest possible arrival.
The full The ii–V–I reference → covers variations, songs built on it, and the pattern in every key.