Key and Key Signatures
When a song consists of notes from a particular scale, it is said to be written in the key which has the same name as that scale. For example, if a song contains notes from the G major scale, it is said to be in the key of G major. Instead of writing a sharp sign before every F# note, it is easier to write just one sharp sign after the treble clef. This means that all F notes on the staff are played as F# even though there is no flat sign placed before the note. This is called a Key Signature. A key signature consists of one or more sharps or flats written after the treble clef, or in the case of the key of C major no sharps or flats. Because the G major scale contains the note F#, the key signature for the key of G major will consist of an F# note written after the clef.
This is the key signature for the key of G major. It has one sharp sign after the treble clef.
The C major scale contains no sharps or flats, therefore the key of C major contains no sharps or flats.
Here is an exercise to help you become more familiar with the notes of the G major scale. Notice the key signature for the key of G major.
Here are two songs which you have already learnt in the key of C major. They are written here in the key of G major. Changing the key of a piece of music is called transposing. This will be discussed more on the following page.
