Double Sharps

So let’s continue applying the rules:

From C# we go up five steps:

C# D# E# F# G#

So the next key in the circle of fifths is G# major.

G# A# B# C# D# E# F# G#

The rules say we should now add a sharp to the 7th note and we can see that this is necessary to maintain the major scale formula:

G# [T] A# [T] B# [S] C# [T] D# [T] E# [T] F## [S] G#

F## sounds the same as G but we can’t call that note G in a key where we already have a G#.

Now you might complain that you have never seen a piece of music written in a key with double sharps (they do exist, but are exceedingly rare). Later on we’ll discover exactly why this is.

However, even if you never play in these keys, it is important to understand the concept because, if you go on to study harmonizing (which is probably the most interesting and useful section of music theory for guitar players), you will need to be able to carry out theory work in all keys, including those with double sharps.

So onwards:

The next key in the circle is:

G# A# B# C# D#

D# major.

It has 9 #s :

D# E# F## G# A# B# C## D#

Then up five to A# major with its 10 #s:

A# B# C## D# E# F## G## A#

And up another five steps to E# major with 11 #s:

E# F## G## A# B# C## D## E#

And finally we might imagine that the next key would be B# with 12#s:

B# C## D## E# F## G## A## B#

But if we look closely we can see that:

B#=C, C##=D, D## = E, E# =F, F##=G, G##=A, A##=B, and B#=C

So we are now truly back at the start of the circle in the key of C major which has no sharps.

C D E F G A B C

So that’s the circle of fifths, but, for every key with sharps in the key signature there is one that sounds the same, but uses flats instead of sharps. You can read all about flat keys in the circle of fourths.

If you have already sorted the circle of fourths out then take a look at the second part of the Key signatures page where we bring all this magical stuff together so that it (hopefully) makes sense!

Bookmark this page:
delicious digg reddit facebook stumbleupon bebo my space live spaces