http://www.youtube.com/watch?v=Qpyu8hgIepE
In general, less grandiose and scale. Less... melodic. But louder, and quicker. Fits theory of increased data consumption of people (as time progresses), loud and quick sounds. At the same time I noticed a reduction in the amount of people it takes to make music. A more human element as it progresses to modern times. Ha ha... trends.
Edit
Depending on how humans evolve or don't I can see two distinct possibilities. Assuming this trend continues.
Edit
I also notice the songs become less dark and grim, and happier. Ha Ha... social pacification.
Edit
Then there was Techno... which was one of the oddballs in there. lol