Tracing the Musical Saga of Mass Effect

Realizing that the score changes quite a bit between the original Mass Effect and Mass Effect 3, Kotaku takes us through "the musical saga of Mass Effect" by embedding and commenting on several tracks that BioWare's audio team used throughout the series. It's difficult to quote anything about the tracks themselves, so I'll grab a bit from their intro:
There was a time when the story had a fairly straightforward theme, using electronic and orchestral sounds to draw us into a sweeping space opera with dark tones around the edges. Back then, of course, it was a more straightforward story.

It was a theme in an even time a nice predictable 3/4 and it moved with a melody you could hum. It was a theme you could take with you, as a Spectre and member of the Alliance Navy, to march into battle against a single, known enemy.

But as we all know by now, the story of the Mass Effect series doesn't stay simple. It twists and branches, and the reapers eventually become a threat too devastating to imagine on a scale too wide to understand. But it's still Commander Shepard's story, and it's still Mass Effect. So where does the music go, as Shep shifts from new Spectre, to would-be pawn of the Illusive Man, to humanity's or, really, the galaxy's last desperate hope?