If you are guitarist then you should hear the word "key" or a scale or music is in certain key. Key is the root note of a scale or chord progression. It tells us which note are to be played or used in a particular scale. If a piece of music is made up from the notes of F major scale it means that it is in the key of F major. In same way if a piece of music is made up from the notes of G minor scale then it means it is in the key of G minor scale. All the other notes in that piece of music will be heard in relation to G minor key note.
Key signature are used to label keys and to indicate what notes must be raised or lowered in order to maintain the same intervals for the major and minor scales. The key of C major is the simples because it does not have any sharp or flats. The G major is the second simplest key which only contains one sharp note and the third is the key of F which only contains one flat note.
Key of C major:- C D E F G A B C
Key signature are used to label keys and to indicate what notes must be raised or lowered in order to maintain the same intervals for the major and minor scales. The key of C major is the simples because it does not have any sharp or flats. The G major is the second simplest key which only contains one sharp note and the third is the key of F which only contains one flat note.
Key of C major:- C D E F G A B C