I'll post some of it here as well:
Achron has a four dimensional story which begs for an engaging sort of storytelling -- something with some darkness, gravity, and emotion to it. When I started working with Hazardous Software on music for Achron, there was not yet a visual artistic concept to coordinate with, which meant there was quite a bit of back and forth between myself and Chris about storyline and motivations. We determined that there would be a few key factors to account for in the music. One would be that it should be something one could listen to for an hour at a time without going crazy. While it cannot be confirmed that this will make the final cut, our current intentions are to use tracks which are significant in length, so as not to be an afterthought.
Another major consideration was that there was a story to tell and epic themes were going to factor in. The bottom line is that I did not want to get lost in a generic feeling of military or sci-fi cliche. I wanted to use the music to emphasize story elements.
Because the story begins from the human perspective and much of the story involves being somewhat achronal, we mixed themes of bravado, arrogance, regret, and loss, which accompanies a people who are, for all intents and purposes, lost in space that they had previously conquered. At the same time, these people still have something to lose which is worth fighting for, so that sense of urgency and non-hopelessness has to be inherent.
For the Vecgir, we described their context for being with themes of brokenness, freedom, individualism, and tribal instinct.
The Grekim are a discussion for another day.