So... here's a bit of a technical question.

For the most part I love the music, but as I play this game for such a lengthy period of time the battle songs tend to get a little repetitive. I'd like to see about changing or replacing the music files. Unfortunately, I have no clue how I would reach them since I don't see any music files in a regular format. I wager that they're encrypted into the data main files of the game and that changing them would be no easy task.

Does anybody know how to do this?

In specific I would like to change the tracks "Resounding Hammer" and "Howling Roar" (the "default" battle music).

Before anyone suggests it, I'm not interested in muting anything.

That's pretty easy.
You need to put the replacement music file into either the game folder or /patch folder, and name it "BGM$$$.OGG"; $$$ is a number for each track, it's generally the same as the track order in the music room (it's easy to trial-and-error it; you can change files even without exiting the game/music room).
I too changed the workshop music because it was annoying.

Excellent. That was much simpler than I thought it'd be.

Thank you. In your honor, my good sir, I will be using worldendDominator from my Umineko folder as a BGM.

Playing Kamidori is much smoother with custom tracks.