It's a mix of Battlefield and Precious Jerusalem, both by Blind Guardian, as well as Bye Bye Beautiful by Nightwish. The first is a theme possibility for a part of one of my books, the second seems to fit just something I've been thinking about (and is beyond catchy), while the last has some moral and common sense value to it. They all have my mind captivated and thinking hard, so I have them going through on occasion.