The notation below shows all twelve notes used in western music The "in between" notes are written here as sharps. This is called a chromatic scale. Chromatic scales consist entirely of semitones (i.e. they move up or down one fret at a time) and the start and finish notes are always the same (the keynote or tonic). The chromatic scale uses all twelve notes used in western music and can begin on any note. Note that in the example below# there are no sharps between B and C# or E and F. This is because they are a semitone apart and there is no room for an extra note between them.
This is a natural sign.
A natural sign cancels the effect of a sharp or flat for the rest of that bar, or until another sharp or flat sign occurs within that bar.
A sharpened note stays sharp until either a bar line or a natural sign ( @ ) cancels it as shown below.