the frequency variations would cause a different resonance with the listener
I have been trying to find out what the characters of each of the keys are. Do you know them all? I know that D major, for example, is supposed to be martial and F major pastoral (I think) but that's about as far as I can go. I think the point about certain keys sounding good on certain instruments is a valid point but is it cause or effect? D is martial because D is a good key for brass instruments and brass instruments sound martial so when one wishes to write martial music one does so in D so it will sound good on the martial instruments. Perhaps, at some point during the tweaking of the scales to get around the Pythogorean comma, D was more martial feeling because of its particular thirds and fourths and sixths and what-all, so when brass instruments were designed they were designed with the key of D in mind. But would a piece written in D sound less martial if transposed to F and played on a brass instrument designed for F the way a normal brass instrument was designed for D?
