Keys that have Signatures
| ♮ |
♯ |
♭ |
| Major |
Minor |
Major |
Minor |
Major |
Minor |
| A |
a |
— |
a♯ |
A♭ |
a♭ |
| B |
b |
— |
— |
B♭ |
b♭ |
| C |
c |
C♯ |
c♯ |
C♭ |
— |
| D |
d |
— |
d♯ |
D♭ |
— |
| E |
e |
— |
— |
E♭ |
e♭ |
| F |
f |
F♯ |
f♯ |
— |
— |
| G |
g |
— |
g♯ |
G♭ |
Facts to Remember
-
From the circle of fourths / fifths we have:
-
Each sharp signature is a subsequence of
F♯
C♯
G♯
D♯
A♯
E♯
B♯
and starts with
F♯.
-
Each flat signature is a subsequence of
B♭
E♭
A♭
D♭
G♭
C♭
F♭
and starts with
B♭.
-
Except for accidentals, each
sequence is the other, reversed.
-
All natural keys have a signature, major and minor.
-
C and a are the only natural keys with no sharps or flats
in their signature.
-
All other natural major keys except F have a sharp signature.
-
Conversely, F is the only natural major key with a flat signature.
-
Most natural minor keys have a flat signature.
-
b and e are the only natural minor keys with sharp signatures.
-
a, already mentioned, has neither sharps nor flats.
-
The remainder, c, d, f, g have flat signatures.
-
F♯
and
C♯
are the only sharp major keys.
-
b♯
and
e♯
do not exist. All other sharp minor keys do.
-
Neither do
B♯
and
E♯.
-
Therefore, no sharp white piano key has
a key signature, major or minor.
-
a♯
d♯
and
g♯
have no parallel major keys.
-
Except that of F♮,
all flat signatures have a flat root,
major or minor.
-
F♭
and
f♭
do not exist. All other flat major keys do.
-
F♭
is the only flat white piano key having no major signature.
-
Neither flat white piano keys,
f♭
and
c♭
have a minor signature.
-
C♭,
D♭
and
G♭
have no parallel minor keys.
-
The remaining flat minor keys,
a♭,
b♭,
and
e♭,
exist.
-
Given a natural major key not F,
its seventh is the last sharp in
its signature.
-
Example. The seventh of B is
A♯
so its signature is
F♯
C♯
G♯
D♯
A♯.
-
Example. The seventh of G is
F♯
so its signature is
F♯.
-
Example. The signature
F♯
C♯
G♯
is A major since a half-step up
from the last sharp, G, is A.
(The major seventh, or leading tone, is
a half-step below the root.)
-
The signature of F is
B♭
-
Given a flat major key (that exists),
it is the second to last flat in its
signature.
-
Example. The signature of
B♭
is
B♭
E♭.
-
Example. The signature of
E♭
is
B♭
E♭
A♭.
-
Example. The signature of
A♭
is
B♭
E♭
A♭
D♭.
-
Example. The signature of
F♭
is, oops, doesn't exist.
(Use E instead.)
-
Each minor key has the same signature
as its relative major.
-
The relative major of a minor key is its (minor) third.
-
The relative minor of a major key is its (major) sixth.
-
Given a minor key (that exists), find its signature.
-
Example.
The (minor) third of a♯
is c♯ so its signature
is
G♯
D♯
A♯
E♯
B♯
F♯
C♯,
same as
C♯.
-
Example.
The signature of e♯
is, oops, doesn't exist. (Use f instead.)
-
Example. The third of g is
b♭ so its signature
is
B♭
E♭,
same as
B♭.
-
Given a major key (that exists), find its relative minor.
-
Example. The sixth of F is d, its relative minor.
Its key signature is the same as F:
B♭.
-
Example. The sixth of
G♭
is c, its relative minor.
Its key signature is the same as
G♭:
B♭
E♭
A♭
D♭
G♭
C♭.
Alex Notes