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Key Signature and The Circle of 4th/5ths

Key Signatures and The Circle of 4th/5th

Key Signatures

Where key signatures come from.

Key Signatures come from those altered notes from major scales. Any time you alter a note by making it a sharp or a flat according to the major scale formula; that alteration is placed next to the clef and called a key signature.

Order of Sharps

Figure : Treble Clef Sharp Order

TC Sharp Order







Figure : Bass Clef Sharp Order

BC Sharp Order







Order of Flats

Figure : Treble Clef Order of Flats

TC Flat Order







Figure : Bass Clef Order of Flats

BC Flat Order










Circle of 4th/5th

The Circle of 4th/5th

The key signatures ascending from 0 accidentals to 7 accidentals. Flats will occupy one half of the circle the sharps will occupy the other half. The bottom 3rd, aka “the dark side” of the circle will overlap (enharmonic key signatures).


Figure : The Circle of 4th/5th

Circle of 5ths


















Shortcut to figuring out scales

The name of the key is the same as the name of the scale. For Example, if the scale you chose is Ab, look at how many flats or sharps the key of Ab has; in this case it has 4 flats. In this example, you must start with an Ab and end the scale with an Ab eight notes higher or lower than the one you began with. Look at the mnemonic for the flats: Battle Ends And Down Goes Charles Father. What are the 1st 4 words?: Battle, Ends, And, Down. This means that the key of Ab major has four flats and the flats are in order: Bb, Eb, Ab, Db. The scale has to start with Ab and end with Ab. So the scale in order would be: Ab, Bb, C, Db, Eb, F, G, Ab

Major scales and minor scales have to proceed in sequence no matter what note they begin on. So if the scale begins on A the next note has to B, then C, etc…. If the scale begins on D, the next note is E, then F, etc…

Key Signature






















Worksheets 29-32

Worksheets 33-36

Worksheets 37-40