One way to learn your key signatures is this:

Key Signatures with Sharps

Take the Cmajor Scale – it has no sharps or flats,

C D E F G A B C

Count up five degrees of the scale to G

Start the scale from G,

G A B C D E F G – add the sharp – this is a semitone down from the first note – therefore our sharp is F#

So now G major looks like this:

G A B C D E F# G

Count up five degrees of the scale to D,

Start the scale from D,

D E F# G A B C D – add the sharp – this is a semitone down from the first note – therefore our sharp is C#

So now D major looks like this:

D E F# G A B C# D

Count up five degrees of the scale to A,

Start the scale from A,

A B C# D E F# G A- add the sharp – this is a semitone down from the first note – therefore our sharp is G#

So now A major looks like this:

A B C# D E F# G# A

Count up five degrees of the scale to E,

Start the scale from E,

E F# G# A B C# D E- add the sharp – this is a semitone down from the first note – therefore our sharp is D#

So now E major looks like this:

E F# G A B C# D# E

Count up five degrees of the scale to B,

Start the scale from B,

B C# D# E F# G# A B- add the sharp – this is a semitone down from the first note – therefore our sharp is A#

So now B major looks like this:

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

Key Signatures with Flats

Take the Cmajor Scale – it has no sharps or flats,

C D E F G A B C

 

Count up Four degrees of the scale to F

Start the scale from F,

F G A B C D E F- count up four degrees to B flatten this note so it becomes Bb (THIS WILL ALSO BE THE START OF YOUR NEXT SCALE)

So now F major looks like this:

F G A Bb C D E F

Count up Four degrees of the scale toBb

Start the scale fromBb,

Bb C D E F G A Bb- count up four degrees to E flatten this note so it becomes Eb (THIS WILL ALSO BE THE START OF YOUR NEXT SCALE)

So now Bb major looks like this:

Bb C D Eb F G A Bb

Count up Four degrees of the scale toEb

Start the scale fromEb,

Eb F G A Bb C D Eb– count up four degrees to A flatten this note so it becomes Ab (THIS WILL ALSO BE THE START OF YOUR NEXT SCALE)

So now Eb major looks like this:

Eb F G Ab Bb C D Eb

Count up Four degrees of the scale toAb

Start the scale fromAb,

Ab Bb C D Eb F G Ab– count up four degrees to D flatten this note so it becomes Db (THIS WILL ALSO BE THE START OF YOUR NEXT SCALE)

So now Ab major looks like this:

Ab Bb C Db Eb F G Ab

Count up Four degrees of the scale toDb

Start the scale fromDb,

Db Eb F G Ab Bb C Db– count up four degrees to G flatten this note so it becomes Gb (THIS WILL ALSO BE THE START OF YOUR NEXT SCALE)

So now Gb major looks like this:

Db Eb F Gb Ab Bb C Db