Each Key you learned in the previous lesson has its character or signature, in music, we call it a “Key Signature”.
The key Signature is the number of sharps or flats a key possesses.
For instance, the key of C has no sharps or flats while the key of F has 1 flat. This defines the difference between the key of C and F.
The importance of knowing the key signature can’t be overemphasized, it’s needed for proper note nomenclature (naming) in each key. Music has rules and you don’t want to start with spelling notes wrongly, once you can identify the key signature of a particular key, you can’t go wrong spelling notes wrongly.
let’s examine the difference between the Key of F and G for instance.
The key of F has a black note in the F major scale, this is also the same for the G major scale.
So how then do we differentiate both keys? By spelling their notes properly for each key and it’s only the Key Signatures that will help us here.
By music theory, the key of F has one flat while the key of G major has one sharp.
Why is it like that? Good question
The number one rule of notes nomenclature is :
No letter should repeat itself while spelling the Major Scale (key)
You can’t say the F major scale is F,G,A,A#,C,D,E and F Already it conflicts with our sight seeing A and A# together… “A” is repeated twice which is wrong even though it’s practically right yeah.
It’s both theoretically and practically accurate to use the enharmonic equivalent(second name) of A#(A sharp) which is Bb (B flat).
Now the proper F Major Scale is spelled F,G,A,Bb,C,D,E, and F (it settles fine with our sight)
Don’t forget we need to think of the key of G Major too
if you spell the G Major Scale as G, A,B,C, D,E, Gb and G
It it wrong because G is coming in twice G & Gb again. Hence what’s the enharmonic equivalent of Gb? It’s F#
So the proper G Major Scale is G, A, B, C, D, E, F# and G.
Now you see why the F Major is strictly having a key signature of 1 flat while the key of G Major has 1 sharp. They are both single black notes in each key but still differ by the key signature.
That being said , Can you get the rest key signatures for each key?