Key Signatures And The Circle Of Fifths

Key Signatures And The Circle Of Fifths

A 'key signature' shows up at the very beginning of a piece of music, directly after the clef;

The key signature tells you two things; the name of the key and what flats or sharps, if any, are to be applied in the music. 

Flats or sharps that appear in a key signature apply to the entire piece, which is different than when they are used as accidentals.
 You can learn more about sharps, flats and accidentals by watching this short video; Accidentals, Whole Steps and Half Steps.

There is a scale that goes with each key that starts on the same note as the name of that key. For example; for they key of G Major, the scale would start on G. Any sharps or flats that are in the key signature would apply to that scale. For example; the key of G Major has one sharp which is F, so the scale of G would have an F sharp in it.


There is a system to the key signatures and understanding it makes using key signatures much clearer and easier.
The first step is to learn the order of the sharps and flats because they are always used in the same order;


The order of the sharps is F C G D A E B.
You can use the nemonic; Four Cats Go Dancing And Eat Birds to help you remember this.
So, if a key signature has one sharp it is F;



If a key signature has two sharps, they will be F and C;



If a key signature has three sharps, they will be F C and G;



And so on, always using the sharps in that specific order.


The order of the flats is; B E A D G C F.
The nemonic you can use for this is; Barney Eats And Drinks Garbage Can Food.


So, if a key has 1 flat, it is B;



If a key has two flats, they will be B and E;



And, if a key has three flats, they will be B E and A;



The Circle Of Fifths

Lastly, all the keys are arranged in what is known as 'The Circle of 5ths.' 

A 5th is an interval, so this is saying that each key is the interval of a 5th from the last one.
The 'Circle' starts with C Major, which is the only key that has no sharps and flats (all notes being naturals). On the right side, the sharp keys go upwards by fifths and add one sharp each time.
On the left side of the circle, the flats go downward by 5ths, adding one flat each time.
It is important to note that these are 'Perfect 5ths' and so, for example, you go from B to F sharp and not F natural on the sharp side and you go from F down to B flat, not B natural on the flat side.



Learn more about Intervals and Their Qualities.

There are a couple of short-cuts to reading key signatures, but the above information is still vital as you need to know what sharps or flats to apply to your music to be able to play in the right 'key.' Practicing the corresponding scale to the key you are working in is the quickest way to master a particular key.


Get 'The Book Of Music Basics' on Amazon