Minor keys and the harmonic minor
Relative keys
Every key signature belongs to two keys: a major key and its relative minor. The relative minor starts on the 6th degree of the major scale, which is three semitones (a minor 3rd) below the major key note.
| Key signature | Major | Relative minor |
|---|---|---|
| none | C major | A minor |
| F sharp | G major | E minor |
| B flat | F major | D minor |
Going the other way, the relative major is three semitones above the minor key note.
The harmonic minor scale
A minor scale starts from the notes of its key signature. In the harmonic minor, the 7th note is raised by a semitone, going up and coming down. That raised 7th is a semitone below the key note, so the scale leads strongly home.
The raised 7th is always written as an accidental: it is never in the key signature.
- A minor: G sharp.
- E minor: F sharp (key signature), and D sharp (raised 7th).
- D minor: B flat (key signature), and C sharp (raised 7th).
Worked example: one signature, two keys
A key signature has one sharp. Which major key and which minor key share it?
- One sharp, F sharp: G major.
- The relative minor starts on the 6th degree of G major: G, A, B, C, D, E. So E minor.
Tip: do not mix up the relative minor with the minor key on the same letter. G minor is a different key; the minor that shares G major's key signature is E minor.
This question is in Brainlag Plus