🔑 Circle of Fifths Explorer
Choose a key to see its signature, relative minor and closely-related keys — a fast reference for reading music, transposing, and understanding how one key leads to the next.
🔑 C major
Closely related keys: Am, G major, Em, F major, Dm
The mapmaker's tool for harmony
Because roots in jazz so often move by fifths, the circle is the quickest way to see where a progression is heading and which keys sit next door. It also makes key signatures something you can reason about rather than memorise.
Pair it with the Jazz Chord Progression Generator to watch a ii–V–I trace a path around the circle, and the Scale & Mode Finder to spell the notes of any key you land on.
❓ Frequently Asked Questions
What is the circle of fifths?
It arranges the twelve keys so each step clockwise moves up a perfect fifth and adds one sharp (or removes one flat). C sits at the top with no accidentals; going clockwise gives G, D, A and so on, while going anticlockwise gives F, B♭, E♭ into the flat keys. It's a map of how keys relate.
How do I read a key signature from it?
The position tells you the count and the order. Sharps are added in the order F C G D A E B, so G has one (F♯) and D has two (F♯, C♯). Flats follow the reverse order B E A D G C F, so F has one (B♭) and E♭ has three (B♭, E♭, A♭).
What is a relative minor?
Every major key shares its key signature with a minor key a minor third below — its relative minor. C major and A minor both have no sharps or flats; G major pairs with E minor. The two keys use the same notes but centre on different tonics.
Which keys are closely related?
The keys nearest on the circle differ by just one accidental and share most of their notes: the dominant (a fifth up), the subdominant (a fifth down), and the relative minors of all three. Music modulates smoothly between these closely-related keys, which is why they're grouped here.