What are the different signatures and keys of music?

There are a total of fifteen keys in Western music. Keys come with two forms, sharp keys and flat keys and one comes with all naturals. The complete list of major keys are shown below:

C major (or A minor) - no sharps/flats

G major (E minor) - 1 sharp

D major (B minor) - 2 sharps

A major (F-sharp minor) - 3 sharps

E major (C-sharp minor) - 4 sharps

B major (G-sharp minor) - 5 sharps

F-sharp major (D-sharp minor) - 6 sharps

C-sharp major (A-sharp minor) - 7 sharps

F major (D minor) - 1 flat

B-flat major (G minor) - 2 flats

E-flat major (C minor) - 3 flats

A-flat major (F minor) - 4 flats

D-flat major (B-flat minor) - 5 flats

G-flat major (E-flat minor) - 6 flats

C-flat major (A-flat minor) -7 flats

There you go, those are all the different keys you can write in!