Thanks for catching that! This pack was kind of an oddity. A very long time ago it was an exclusive in a Humble Bundle, but years later the rights to it were returned to me and I listed it here, so it's sort of obscure. I guess that track omission slipped past my QA team, which consists of... me! So I will give myself a stern talking to, and will fix this up in the morning.
Viewing post in Modern Day Music Mini-Pack comments
Resolution to the mystery: I may not have intended to include War Room in the pack, as it was supposed to be 5 tracks, 5 ME for $5, but I'm listing it as a bonus track and now the download has both the .m4a and the .ogg in it, giving the pack six total music tracks.
So, you and anyone else can just re-download to grab the .ogg (which loops better than if you were to make an .ogg of the .m4a)