This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The key approach to understanding music is to understand music as a form of belonging: typically, a sense of belonging to a shared culture, belonging to an ethnic, political, mythological, gendered or geographically bounded nation or community where people share music, dance, stories, ideas, practices and experiences. The key point in understanding authenticity today in traditional music is to understand that it is a social concept, used, defined and discussed by the communities that participate in traditional music and who use ideas about the authenticity of material and performance to establish the boundaries of ways of belonging to the community. In Scotland three languages are spoken today that are key to understanding traditional music namely: English, Gaelic and Scots. Today, it is widely accepted in ethnomusicology that a nation's traditional music, or a regional musical culture cannot simply be defined by its sonic characteristics.