The circle of fifths, that actually does something.
Click any key. You get its signature, its scale, its relative minor, and every chord that belongs to it — shown on the keyboard as well as named.
Click a key, or focus the wheel and use ← → to step round in fifths.
C major
Relative minor — A minor
Key signature
Scale
Chords in this key
On the keyboard
The part most versions skip
Why the keys are in that order
The circle isn’t a design choice. It’s what happens when you keep counting up five letter names and write down where you land.
Each of those steps adds exactly one sharp to the key signature. Go the other way — counting down instead of up — and each step adds one flat. That is the entire construction, and it is why keys sitting next to each other on the wheel share almost all of their notes.
Find a key signature
Count the steps from C. Three clockwise is three sharps. Two counterclockwise is two flats.
Find the chords in a key
Your key plus its two neighbours are the major chords. The three inside them are the minors.
Change key smoothly
One step round sounds natural. Halfway across sounds like a deliberate jolt — sometimes exactly what you want.
Keep going
Read the theory behind it
What the circle is for
The long version, with the three questions it answers faster than working them out.
Read →Key signatures explained
Why the sharps always appear in the same order, and how to name the key from them.
Read →The music theory path
Six steps, in order. The circle sits at step six for a reason.
Start →