Guess the Key Signatures by Unknown

Songs
#1

Guess em.

#2

Sheet 0 is C# minor.
Sheet 1 is ???. It would be G major without the sharp A
Sheet 2 is E lydian with flat-seven (more of a scale than a key)
Sheet 3 is C major.
Sheet 4 is B major.
Sheet 5 is A-flat major.

#3

Sheet 1 is B neopolitan

#4

FUUUUU I was going to write that!
Hmph, it’s B neapolitan minor, by the way.
And it’s a scale, not a key!!!