Tool
Circle of fifths
Every key arranged by the fifth that separates them, with its key signature, its relative minor and its neighbours.
Each step clockwise rises a fifth and adds a sharp; each step anticlockwise falls a fifth and adds a flat. The inner ring holds the relative minor of each key, which shares its key signature. Click a key.
C major
No accidentals
- Relative
- — the same key signature, in the other mode.
- Parallel
- — the same tonic, in the other mode.
- A fifth above
- — the dominant's key; one accidental more.
- A fifth below
- — the subdominant's key; one accidental fewer.
The circle of fifths
The circle of fifths sets the major keys around a circle in which each one lies a perfect fifth from its neighbour. From C major, with no accidentals, each step clockwise goes up a fifth (G, D, A, E) and adds a sharp to the key signature; each step anticlockwise goes down a fifth (F, B♭, E♭, A♭) and adds a flat.
Key signatures
A key signature is the set of sharps or flats written at the start of the staff, which holds for the whole piece. Sharps always enter in the same order, F, C, G, D, A, E, B, and flats in the reverse order, B, E, A, D, G, C, F. Each key on the circle keeps the accidentals of the one before and adds the next in the order.
Enharmonic keys
At the bottom of the circle the two sides meet. B major, with five sharps, sounds the same as C♭ major, with seven flats; F♯ major, with six sharps, sounds the same as G♭ major, with six flats; C♯ major, with seven sharps, sounds the same as D♭ major, with five flats. These keys are enharmonic: the same keys of the piano, written two ways.
Relative and neighbouring keys
Each major key has a relative minor with the same key signature, whose tonic lies a minor third below: A minor for C major, E minor for G major. On the circle, the relative minor appears on the inner ring, beside the major.
Two neighbouring keys on the circle differ by a single accidental and share their other six notes. Modulation between neighbours is the most frequent in tonal music: from C major, the usual destinations are G major, F major and the relative minors of all three.
