(MJS) Major Key Signatures Lesson
Major Key Signature
A key signature is a collection of every accidental found in a scale.
To demonstrate this, we will use the key of A Major, which has three sharps.
A key signature can be used instead of writing a sharp next to every C, F, and G.
As you may have noticed, the sharps are arranged in a special order.
F# comes first, followed by C# then G#.
Next comes D#, A#, E#, and finally B#. You can remember this order by using the following saying: 'Father Charles Goes Down And Ends Battle' or 'Francis Can Go Down And Eat Breakfast".
Starting with Bb, the order of the flats is the exact opposite as that of sharps. The sharp order was FCGDAEB and the flat order is BEADGCF.
Next comes Eb, Ab, Db, Gb, Cb, and finally Fb. This order can be remembered with another saying: 'Battle Ends And Down Goes Charles' Father' or the word BEAD and then Good Corn Flakes.
30 different key signatures exist (15 for major scales and 15 for minor scales). Most theory students are expected to memorize all 30. Fortunately, there are several methods for identifying major key signatures.
You must memorize that the key of C major has no sharps or flats.
You must also memorize that the key of F major has only one flat (Bb).
For all other flat key signatures (other than F major), you can locate the second to the last flat and that is the key. In the key signature above, the three flats in order are Bb, Eb, and Ab. The second to last flat would be Eb and that is the name of the major key signature with 3 flats.
The second to the last flat listed above is Cb and therefore the name of the major key signature with seven flats is Cb.
For major key signatures that contain sharps, you take the last sharp of the key signature and go up a half-step. In the key signature shown here, the last sharp is G# and so by going one half-step above G# we find the note A. The name of the major key signature with three sharps is therefore A major.
By taking the last sharp of the above key signature (B#) and going up one half-step, we come to C#. Therefore the name of the major key signature with seven sharps is C# major.
You can the sidebar resource for work on identifying major key signatures.
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