Key names

By Vidas Pinkevicius

​Are you wondering how the keys based on degrees of the major or minor scale are related to the home key (the tonic)?

There are only 3 main functions (the tonic, the subdominant, and the dominant). The rest of the keys are their relatives.

Let's take some major key as an example:

1st scale degree key is the tonic.
2nd scale degree key is relative of the subdominant.
3rd scale degree key is relative of the dominant.
4th scale degree key is the subdominant.
5th scale degree key is the dominant.
6th scale degree key is the relative key.
7th scale degree key isn't related to the tonic at all because you can't build a major or minor chord on it out of the notes of the home key.

But with minor keys it's different:

1st scale degree is the tonic.
2nd scale degree key isn't related to the tonic at all because you can't build a major or minor chord on it out of the notes of the home key.
3rd scale degree is the relative key.
4th scale degree is the subdominant.
5th scale degree is the dominant.
6th scale degree is the relative of the subdominant.
7th scale degree is the relative of the dominant.

What does it all mean?

It means you can play the C major scale and build major and minor chords solely out of the white notes - C major, D minor, E minor, F, major, G major, and A minor (B minor is diminished triad so it doesn't count).

If you start with the A minor scale, the chords will be - A minor, C major, D minor, E minor, F, major, and G major (B minor again doesn't count).

A good exercise is to play some other scale and try to discover related keys. Make sure you use the notes and the accidentals of that major or minor key only.