Interactive circle of fifths

Reading the circle

The outer ring holds the major keys, a perfect fifth apart going clockwise: C, G, D, A and on round. Each step clockwise adds one sharp to the key signature, or takes away a flat. Going counter-clockwise does the opposite, which is why the flat keys sit on the left: F, B♭, E♭.

The inner ring gives each major key’s relative minor — the minor key with the same signature, three semitones lower. C major and A minor share no sharps or flats; G major and E minor share one sharp.

Keys that sit next to each other share six of their seven notes, which is why music moves between neighbours so easily and why the chords I, IV and V of any key are the key itself and its two neighbours. At the bottom, one position has two names — F♯ major and G♭ major are the same keys on the piano, written with six sharps or six flats — and the explorer lets you choose the spelling.

What people use it for

• Working out a key signature: count the steps from C.
• Finding the chords likely to turn up in a song: the key and its two neighbours.
• Planning a key change that will sound smooth: move one step.
• Remembering the order of sharps (F C G D A E B) and flats (B E A D G C F).

The circle of fifths lesson explains why the circle closes, and how to use the circle of fifths works through each of these uses.