Every piece of music is written in one key or another, such as the key of Bb or the key of E or whatever. The key signature at the beginning of a score tells what sharps or flats are being used in the song, and therefore what scale the song is based on.
Each piece of music contains a key signature. This is written immediately after the clef (on the staff) and is represented by a number of sharps (#) and flats (b). If you look carefully at the beginning of each line of music, you will see a group of sharps or flats (they are never used at the same time). These are placed individually on either a line or a space of the music staff and are placed on the notes they affect. In other words, if a sharp (#) is placed on the top line of the music staff, the note F is played as an F#. And all occurrences of the note F, whether on the top of the staff, the first space of the staff, or above or below the staff (marked by ledger lines), are played as an F#.
If a note that is dictated as sharp or flat by the key signature is to be played as natural, an accidental is placed before the note. For example, if an F (natural) is to be played in the key of G, an accidental has to be placed before it so it is not played as an F#.
The key signature is used so that the number of sharps or flats that are used in within the music itself will be limited. With this said, the musician can tell from the start that each time the note F is played it is to be played as a #. There is no need to put the # in front of each and every F note in the sheet of music. If the signatures were not used, the music would be very hard to decipher because there would be flats and sharps scattered throughout the music, causing cluttering on the lines of music.
The most common key signatures are listed below along with the notes that are affected by them:
Key of C: Includes no flats or sharps
Key of G: Includes one sharp (F#)
Key of D: Includes two sharps (C# and F#)
Key of A: Includes three sharps (G#, F# and C#)
Key of E: Includes four sharps (D#, F#, C# and G#)
Key of F: Includes one flat (Bb)
Key of Bb: Includes two flats (Eb and Bb)
Key of Eb: Includes three flats (Ab, Eb, and Bb)
There is also a relative minor assigned to each key. While it is true that in nearly all ways the major and the relative minor that coincides with it are similar (they use the same scale even though they begin in different places), they are not considered the same. The note that can be found a minor third down from the major (key) is called the relative minor. You can think of it in another way by remembering the sixth note in the major scale is the relative minor. As an example, The C major scale has a sixth note of A so an A minor is the relative minor to C. It is very common to use the relative minor of the key and if you gain a good understanding of them you will find that you have a better understanding of the chord progressions in the song.
Below are some of the keys and their relative minors (keys):
A minor is the relative minor for C.
B minor is the relative minor for D.
F# minor is the relative monitor for A.
G minor is the relative minor for Bb.
An experienced musician playing in a non-formal setting (not using written music) simply needs to know the key to a particular song to be able to play the chords and scales (melodies) for that song.
Last of all, it is very common for a song to change keys before the end of the song. Musicians that are newer to the musical industry may find this very challenging.
Find out more about how to tell the key of a song. Visit Michelle Edward's site on how to choose the best Casio keyboard for your needs.
