Chord functions

You can build the chords of a key (level 41). This level goes the other way: given a chord and a key, say which of the seven it is. That number is the chord's function.

Count from the key root to the chord root along the scale. Am in C major starts on the 6th degree, so it is chord vi.

The numeral's case carries the quality: upper case is major, lower case minor, the ° mark diminished. That is why vi and VI are different answers.

count scale steps from the key root to the chord root

A, C, E inside C major: the chord on the 6th degree, vi.

Practise this in the trainer — it opens with this lesson the first time the concept comes up.