If you are trying to mess with this in C2C, don't. It has some Python that does things for sound. If you just want to add tracks for an era all you need to do is put them in the Sounds/Soundtrack/EraNew folder where "EraNew" is the one for the era the music file goes with like AncientNew or ClassicalNew. When you start the game up it should automatically edit the XML for you and move the mp3 file into the non-New folder. This is done by the MusicUpdate.py file in the Python/AIAndy folder, if you were wondering.