Keys

What this section teaches

A key is a scale with a government. Choose one note as the tonal center, build its major or minor scale, and every note and chord acquires a rank and a role: the tonic rules, the dominant applies pressure, and the other degrees fall into place around them. Harmonizing the scale in thirds yields the key's seven diatonic chords — the native palette nearly every song in that key draws from — and Roman numerals (I, ii, V…) name those chords by their position rather than their letter, which is what makes harmony portable across all twenty-four keys.

How to use these pages

Each key's page lays out its scale, its seven diatonic chords with numerals and note spellings, and its nearest relations: the relative key that shares every note, and the parallel key that shares only the tonic. Use it to answer the practical questions — what chords live in E minor? what is the V of A major? — or to translate a progression you know into numerals so you can carry it anywhere. Songwriters: when a chord in your draft feels imported, check it against the key's table; if it isn't there, you've either borrowed or modulated, and both are covered in the harmony guides.

Where to go next

See how the twenty-four keys arrange themselves into a map on the circle of fifths, how their chords chain into progressions, and how songs travel between keys in how keys relate.