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Music theory definition

Relative key

A major and minor key that share a key signature, like C major and A minor.

Relatives share a signature

C 's starting on A = A . Same signature: .

Learn it in context

This term is introduced in Unit 6: Keys. Work through the explanations and exercises to connect the definition with music.

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  • Circle of fifths

    Every key, arranged so neighbours share all but one note. Tap a key to turn the circle, see its signature, and hear its chords.

Key
The set of notes (and the tonic) a piece is built around, like C major or A minor.
Key signature
The sharps or flats at the start of each line, telling you which notes to play sharp or flat throughout.
Circle of fifths
All twelve keys arranged so each neighbour is a perfect 5th away and differs by one sharp or flat.
Parallel key
A major and minor key that share a tonic, like C major and C minor.
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