If D-sharp minor must absolutely be used , one should take care that B-flat wind instruments be notated in F minor , rather than E-sharp minor ( or A instruments used instead , giving a transposed key of F-sharp minor ) , and E-flat instruments in C minor instead of B-sharp minor , as key signatures do not use double sharps .
If D-sharp minor must be used , B-flat wind instruments should have their parts written in F minor , rather than E-sharp minor .