Reply To: C# concert scale question
I think the discussion we’re having here is exactly what you should be telling your students. The truth is that they are theoretical scales that exist, but aren’t used. As a professional musician, the only time I’ve ever played in C# instead of Db is when I’m accompanying a soloist who would rather see a C# than a Db. For practical purposes, musicians will “transpose” in their heads or even rewrite as necessary.
I love these kinds of theory conundrums!