Ancient voices variations

Does anyone have any information on specific changes made to the theme song for different seasons? Like each rendition at least for the first 20 or so seasons features local instruments to the filming location. I’m trying to get more information on specific changes made and instruments used that vary throughout locations. There isn’t much information I can find online besides a few interviews with Russ and his two videos on YouTube about the China and Africa renditions. If anyone has any additional resources or information that would be amazing!