(2.7)  G Major Scale on Staff Lines

The notes of the G Major scale appear on staff lines as shown below.  We can fit three octaves of G Major within the paired staff lines.

Every time a note appears on the F lines, the sharp (#) symbol is put before it as an accidental, to show that it is really F♯.

Because F always means F♯ in the G Major scale, it is inconvenient to do this every time the note is used.  Instead, a sharp can be placed at the start of every staff, to indicate that all F notes are to be played sharp.

This is known as the key signature of the G Major scale.  Only one F line on each clef is marked in this way, even though the treble clef, for example, also has an F in the space between the bottom two lines.

The same three octaves of the G Major scale shown above can now shown more simply as follows.

The note F♯ would be called an accidental in the C Major scale, but not in this case, because it rightfully belongs to the G Major scale.

In fact, F natural is now the accidental, because it does not belong.  The following shows how the note sequence E, F, F♯, G is written in the key of G.

First the natural symbol is used as an accidental, to override the sharp of the key signature, and then the F needs to be 'resharpened' afterwards, with a sharp accidental.

Every key has a different key signature, as we will see shortly.  The absence of a key signature always indicates the C Major scale.

All Major scales apart from C Major have at least one sharp or flat (and most of them have several) but there are no Major keys which have both sharps and flats in their key signature.