Theory · Keys

See how keys sit next to each other.

Move around the circle by fifths, compare relative minors and inspect the diatonic chords inside each major key.

FifthsCA minor

Selected key

C major

Relative minor: A minor

IC
iiDm
iiiEm
IVF
VG
viAm
vii°Bdim

Move clockwise for a perfect fifth. Adjacent keys share most of their notes and often move naturally in harmony.

How to read it

Nearby keys share more notes.

Clockwise movement adds a sharp; counter-clockwise movement adds a flat. The inner label shows the relative minor, which uses the same key signature as its paired major key.

Select a key to see its seven diatonic triads. This makes the circle useful for harmony and modulation rather than just memorizing key signatures.