For the Māori, I'm guessing they'll choose "Pōkarekare Ana" for the main theme. It's our most well-known song, and probably out of copyright by now: In the Ancient Era you could also add a waiata or some kapa haka music. Or some ambient music with traditional instruments (like in the kōauau video on the previous page of this thread). Works well with Australia's didgeridoo music. If you wanted a haka-inspired song, then something like "Tarakihi" would be epic, although that particular song is copyrighted and less well known.