I should probably explain my use of sharps and flats..

In concert band key signatures have either only naturals and sharps or naturals and flats. What happens is some notes are only used as one or the other commonly. With a concert C instrument, like the flute or piano or guitar, you will see Bb or Ab millions of times more than A# or G#, whereas you'll see F# commonly but I've never seen Gb. That's the way it goes for concert music. In order for those exceptions to occur it requires playing in completely queer keys like Db (which is not C#, becuase that note is most commonly seen in the key of Ab. It's the fourth flat of the scale after Bb, Eb, and Ab).