Originally Posted by ednew
The Key of D has two sharps: F# and C#. It has no flats. The third of A Major is C#.
Pet peeve, sorry.
I've never really understood this as I'm not classically trained. It seems like mere semantics to me. Does thinking of things this way help or something? I feel like there's something I'm missing. I realize this may be a complicated answer, but I'm all ears.