The key signature
To show that we want to lower or raise a note, we use accidentals.
The sharp symbol raise a note a half step above it and the flat symbol lower a note a half step below it.
To cancel these accidentals, we use symbols called naturals.
Sharp =
Flat =
Natural =
We need to write sharps or flats symbols in the key signature to show what key we are in.
The key of C major has no sharps or flats because it uses the white keys only.
The key of F major has one B flat in the key signature because all the B's of the F scale are lowered.
See the Circle of fifth to understand how many accidentals we need for one key!
