Originally posted by Stephanie Dawe
Or what about D minor?
Like Bruce said, that's 1 flat, it's the relative minor of F Major.
G7 (mixolydian)?
G Major. If you were simply specifying the key of a song the band knows (i.e. such & such a song, in G) - you'd just specify G Major, which is 1 sharp. Even if the Fs aren't sharp.
B diminished? (lochrian)?
And can you think of any tunes for which you'd want to say "B Locrian" is the key?!?