Why did you need Naxi music for? Just curious. Since I am not into Chinese Min Ge (folk music), I have no idea how their music sounds like, but if you want to know their culture/tradition etc. here's a book that you might enjoy reading: Forgotten Kingdom by Peter Goullart. It is the best amature ethnography you will ever read. If I can be of any help with your Naxi research please feel free to email me.