The circle of fifths, explained like a clock

Twelve keys on a clock

C sits at the top, where 12 o'clock is. Every move one place clockwise goes up a perfect fifth (seven half steps): C, G, D, A, E, B, then F♯, and on around. Every move the other way goes down a fifth: C, F, B♭, E♭ and so on.

After twelve moves you are back at C. It is like a magic staircase that keeps going up and still brings you back to where you started: impossible for real stairs, but true for note names.

One more sharp or flat at each place

A key signature is the group of sharps or flats written at the start of every line of music. It tells you which notes stay sharp or flat all the way through, so they do not have to be written on every note.

C major has no sharps or flats. Each move clockwise adds one sharp: G major has one, D major has two, A major has three. Each move counterclockwise adds one flat: F major has one flat, B♭ major has two, E♭ major has three.

Like adding one candle to a birthday cake each year, the count grows by exactly one each time. So if you know where a key sits, you know how many sharps or flats it has without memorizing a list.

At the bottom of the circle, three keys have two names that sound the same: B and C♭, F♯ and G♭, C♯ and D♭. One is written with sharps and the other with flats.

The order of sharps and flats

Sharps are always added in the same order: F♯ C♯ G♯ D♯ A♯ E♯ B♯. Flats come in the opposite order: B♭ E♭ A♭ D♭ G♭ C♭ F♭. Notice that the order of flats is the order of sharps read backwards.

A memory sentence many English speakers use for the sharps: Father Charles Goes Down And Ends Battle. Read it backwards for the flats: Battle Ends And Down Goes Charles' Father.

Minor twins on the inside

Every major key has a minor key that uses exactly the same sharps or flats. It is called its relative minor, its "minor twin". On the circle the minor key sits just inside its major key: C major and A minor, G major and E minor, F major and D minor.

To find the relative minor on a piano, start on the major key's note and count three keys down, black keys included: C → B → B♭ → A.

Neighbours are best friends

A chord is three or more notes played together. The keys right next to each other on the circle share all but one note, so they sound close and friendly. That is why the three most common chords in a key are the key itself and its two neighbours. In C major they are C, F and G. Musicians number chords with Roman numerals by the scale note they start on: C is the 1st note of C major (I), F the 4th (IV) and G the 5th (V). Capital numerals mean major chords; small ones (ii, iii, vi) mean minor chords. Thousands of songs use just I, IV and V.

The minor chords just inside those three (A minor, D minor and E minor in C major) are friends too. Together these six chords cover most beginner songs. Tap a key on the circle above, then play its friendly chords.

Moving a song to a new key

If a song is too high or too low to sing, you can move every chord the same number of places around the circle. A song using C, F and G moved one place clockwise becomes G, C and D. The song sounds the same, just higher or lower, like turning a dial on the circle.

Every key at a glance

This table shows each major key, its sharps or flats and its minor twin.