Key Signatures

Continuing from last time, let’s finish up key signatures.

To summarise what we have discussed before, C Major and A minor (in its natural form) scales contain no black notes. In order to build major and minor scales starting from any other note, it is necessary to alter one or more notes. For instance, in the scale of G major, note F is sharp.

If you wished to write a melody in G major, you would need to alter all F notes with sharps which would make your sheet music cluttered. Key signatures are used to avoid writing so many accidentals.

Key signatures are placed at the beginning of each staff, between the clef and the time signature:


In the example above, all Fs, Gs and Cs are sharp. These accidentals, affect all of the notes of that name throughout the piece, including those in other octaves. Therefore, if you wanted to change one F to non-sharp (natural) you would need to write a natural symbol before it



The chart above shows how key signatures for given keys are laid out. The green letters in the centre denote minor keys which we haven’t discussed yet.

The first letter of each word in the following sentences tells us the order that the flats and sharps are entered in a key signature:

THE ORDER OF FLATS: Battle Ends And Down Goes Charles’ Father
THE ORDER OF SHARPS: Father Charles Goes Down And Ends Battle


A key signature that uses all seven possible flats will look like this:


A key signature that uses all seven possible sharps will look like this:


In key signatures that contain sharps, to identify the key signature look at the last sharp. The key note will be one semi-tone higher. i.e. the next letter name up the scale. The last sharp indicated above is the B#. Therefore, moving up one step, this key signature belongs to C#-major.

In key signatures that contain flats, to identify the key signature look at the second from last accidental. This is the key note. In this example the second from last flat is Cb. Therefore, this key signature belongs to C-flat major. N.B. F Major has only one flat and so cannot be worked out in this way. This one must just be remembered as must C Major with no sharps or flats.

  1. Hopefully that hasn’t scared you off. 😉 Next time, something more practical for simple songwriting. We’ll be looking at basic chords.

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