The fifth of F# is c# and has seven sharps:—
C# d# e# f# g# a# b# C#
1 2 3∼4 5 6 7∼ 8
In this scale all the notes are sharped. The b# as well as the e# is a white key.
The fifth of C# is g# and has eight sharps. This key necessitates one double sharp and f is double sharped. The double sharps are added in the same order that the single sharps are. The double sharp (designated thus: x) raises a tone one whole step.
G# a# b# c# d# e# fx G#
1 2 3∼ 4 5 6 7∼8
The fifth of G# is d# and has nine sharps (two double sharps, f and c):—
D# e# fx g# a# b# cx D#
1 2 3∼4 5 6 7∼8
The fifth of D# is a# and has ten sharps (three double sharps, f, c and g):—
A# b# cx d# e# fx gx A#
1 2 3∼4 5 6 7∼ 8