My goal in making this was to make a soundtrack to accompany all of the Resident Evil addons, from the RE maps, to the RE infected models. Initially I was going to release one addon with basically the whole soundtrack redone minus the background ambient tracks (rabies, quarantine, etc). I found myself conflicted because I had multiple ideas for certain tracks. For instance, I had several ideas for the tank music, level completion music, and the credits. As a result, I ended up making a collection of addons so that everyone can use the tracks that fit their preferences and wouldn't be stuck with just one song playing every time.

I'm also aware that there are a couple of similar addons or collections that change some of the music, but from what I've seen, those are very random and don't fit the enemies or aren't even from the same game those enemies are from. Also they conflict with other addons. I did my best to make addons for enemies that are their actual themes from the RE games, or in the case where the enemies don't have their own theme music, I at least used music from their respective games.

The majority of these addons are ones that I made, and every addon I made is my original work and not a modified version of someone else's. However, I'll add other addons to this collection by other creators if they are relevant, and especially if they do not conflict with the Resident Evil Zombat Soundtrack (which I consider to be the definitive core of this collection). Combined, we will create the Ultimate Resident Evil Soundtrack for Left 4 Dead 2.