To Guest: maybe we need to hear the music on the original instruments used by the composer to get the original intent. If old instruments are out of tune with modern pitch, that still doesn't negate the idea that the piece was written in a particular key for a reason, although I agree that it would have a different message in a different key.

I firmly believe that different keys have a different feel, different quality, and perhaps even each individul tone has its own character. I definitely notice a difference when I switch a song from one key to another, even by half a step. Pieces that I've done on the piano and then transposed to another key for the violin or guitar are completely different pieces, aside from the different instrumentation. Someone explain to me why.

There was an article in "Bluegrass Unlimited" about the late Roy Huskey, Jr. who was a phenominal musician. He used to say that each room had a note or tone that identified it and each instrument had a sweet spot where it was most resonant.