Understand
Key Signatures and the Circle of Fifths
Which sharps and flats belong to which key, and relative minors.
Class code
YV96Key signatures save writing
Rather than marking the same accidentals in every bar, the sharps or flats a key needs are gathered at the start of each line.
- Sharps always appear in the order F C G D A E B
- Flats appear in the reverse order B E A D G C F
The circle of fifths
Moving up a fifth adds a sharp; moving down a fifth adds a flat. That single idea puts every key in a circle: C, G, D, A, E, B, F sharp going one way, and F, B flat, E flat, A flat going the other.
Relative minor
Each major key shares its key signature with a minor key a minor 3rd below - the relative minor. C major and A minor use no sharps or flats at all.
Quick trick: count down three semitones from the major key name.
Try it
Test yourself