Boiled down to the very core, I think the Imperial March represent Darth Vader's leadership of the Empire, so I actually sometimes say "Vader's theme" and other times "Imperial March", because for me it's like calling our own planet Earth or Tellus, doesn't really matter which because it's the same.

This is what made me decide to use the Imperial March together with the Republic. Because it is the same organization which Anakin Skywalker also plays a big part in. One can't deny the connection between the Republic and the Empire, and since I think the March represents the Empire as well as Vader, I try the best I can to musically link the Republic and the Empire together. I try to tell the story through the music as well as pictures, like the OT so spectacularly did.

I'm glad to hear different opinions though. Makes me contemplate my own ideas more thoroughly.