First of all what is a fifth?

Circle of fifths
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A fifth is an interval (a distance between notes) it is simply the distance between the first note of a sclae and the fifth note of
that scale for example in the key of C a fifth is the distance between C and G. It is very important to remember that it is not just
counting up 5 notes for example in the key of B Major which has F#,C#,G#,D#,A#, if we counted up five notes you would get to F whereas in this
scale the fifth is infact F#.

What does the circle of fifths do?

The circle of fifths is used to work out what the correct accidentals (sharps or flats) are in any given key and to show the
relationship between the various keys.

How does it work?

At the top of the circle we start with C with no accidentals we then simply move up a fifth each time as we progress around the
circle in a clockwise direction.

Each time we move one step around the circle another sharp is added to the scale so C has no sharps we then get G which has one sharp
then D which has two etc.

When we reach 7 steps round the circle we have obviously run out of sharps to add to the list so now we need to add the flat keys
to do this we follow exactly the same procedure but going round the circle in an anti-clockwise direction and this time we go down a
fifth each time so from C we go down to F which has one flat (Bb), if we go down a fifth from F we reach Bb (remembering a fifth is
not always simply fifive notes) and so on.

The sharps or flats are always added in the same order which can be remembered using this rhyme;

Father
Charles
Goes
Down
And
Ends
Battle

reading down the rhyme gives us the order of the sharps and reading it backwards

Battle
Ends
And
Down
Goes
Charles’
Father

gives us the order of the flats.

So G major has one sharp F# and D major has two F# and C#. and so it continues.

Using this method you should be able to work out the key sigature for any major key.

The diagram also shows the minor keys which are related to each major key, for more information on how minor keys work
go to this article.