After many months of work, hurdles, and most of all - procrastination, I have completed my S.T.A.L.K.E.R. - SoC music expansion mod. It can be previewed below, and downloaded here:
Download STALKER Music Expansion
And what a seemingly hopeless battle it was to get this thing done. After doing some research I learned that it wasn't enough to simply save my songs in the ogg format; I had to open them up in a hex editor and copy and paste data from the existing STALKER music. Then run them through some magical command line program, the purpose of which still evades me.
More excitingly: I am now working on Call of Pripyat. And it's going much more smoothly; I'm more motivated and there is no trouble with the files, so I can focus on actually writing music. I've already written about 25 minutes of music, and I'm aiming for 60, so this could be finished quite soon. You can listen to a sample (and see some pretty footage) in the video below.