Related key
Related keys are the keys closely related to the home key of a piece. They share many notes and chords and are easy to reach. In C major these are A minor, G major, E minor, F major and D minor.
- Number
- five per home key
- They include
- relative key, dominant key, subdominant key and their relatives
- In C major
- A minor, G major, E minor, F major, D minor
- Difference from the home key
- at most one sharp or flat
The relatives of the home key
The home key is the key in which a piece begins and ends. Around it lie the related keys: the relative key (same key signature), the dominant key (a fifth higher), the subdominant key (a fifth lower) and the relative keys of the last two. For C major these are A minor, G major, E minor, F major and D minor. On the circle of fifths they lie directly beside the home key.
The tonic triads of the five related keys of C major
From the left: A minor (relative), G major (dominant key), E minor (relative of G major), F major (subdominant key), D minor (relative of F major). All the chords consist of notes of the C major scale. That is the reason for their close relationship.
In the glossary: Relative key · Dominant · Subdominant
Why they are so easy to reach
The related keys have many notes and chords in common. G major differs from C major only in F♯ instead of F, F major only in B♭ instead of B. The relative key A minor has no difference in notes at all. That is why a change there sounds natural and soft. On the page Circle of Fifths it says that neighbouring keys share six of seven notes.
| Home key | Relative key | Dominant key (its relative) | Subdominant key (its relative) |
|---|---|---|---|
| C major | A minor | G major (E minor) | F major (D minor) |
| G major | E minor | D major (B minor) | C major (A minor) |
| D major | B minor | A major (F♯ minor) | G major (E minor) |
| F major | D minor | C major (A minor) | B♭ major (G minor) |
| A minor | C major | E minor (G major) | D minor (F major) |
| E minor | G major | B minor (D major) | A minor (C major) |
| D minor | F major | A minor (C major) | G minor (B♭ major) |
What composers use them for
Composers change to related keys to create contrast without losing coherence. In sonata form the second theme is in a related key, in major movements usually the dominant key, in minor movements usually the relative key. In rondos the episodes are in related keys. Baroque and Classical music mostly moves within this circle.
Distinctions
The related keys must be distinguished from the distant keys, which have little in common with the home key and are usually reached only by detours or cadences. A parallel key, such as C major and C minor, does not count among the related keys either: it shares the tonic and only four of the seven notes.
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Related terms
Relative keyKeyCircle of fifthsDominantSubdominantModulationTonicMinor
Editor: Maik Krohm · reviewed on 3 October 2026
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