Can we compose a remix that came from a music album?
It has to be from a soundtrack, so if you mean an actual music album, probably not (I'd imagine some of the licensing stuff would get more complicated if we could do that but idk). I also assume that, like in the pastime jams, covers have to be of songs that were officially released (someone else can correct me if I'm wrong), but other than that, your choices are pretty flexible! Hope that helps :)