It is not practical to write accidentals throughout a song that uses notes from a particular scale. When a song uses the notes from a certain scale the accidentals for that scale are grouped together at the beginning of the staff next to the clef sign and are applied to the appropriate notes throughout the piece. This grouping of either sharps or flats is called a key signature.
The "E" major scale is shown below with its accidentals. The same scale is shown in the second example and is notated as it would be using the "E" major key signature. The accidentals in the key signature apply to the appropriate notes of the scale.
There is a key signature for each major scale. In addition, each major key signature is shared by a natural minor scale. For instance, "C" major and "a" minor share the same key signature. Click on the buttons below to see how each key signature is written in the treble, bass, alto, and tenor clefs. Notice the order and placement of the sharps or flats for each key signature. The examples represent the correct way to write each key signature in the appropriate clef. (Upper case letters designate major keys and lower case letters designate minor keys.)
Keys which share the same key signature are called relative keys. For instance, e minor is the relative minor of G major and F major is the relative major of d minor. Each major key has a relative minor whose first note is the sixth scale degree of the major key. Each minor key has a relative major key whose first note is the third scale degree of the minor key.
Keys which share the same beginning and ending notes are called parallel keys. For instance, F major is the parallel of f minor. Parallel keys have signatures that differ by three accidentals. (F major has one flat and f minor has four flats.)