A language family is a group of languages related through descent from a common ancestral language or parental language, called the proto-language of that family. The term "family" reflects the tree model of language origination in historical linguistics, which makes use of a metaphor comparing languages to people in a biological family tree.
English for example is a Germanic language, which is a Indo-European language.
It would seem that different people's folk/traditional music are somewhat related to differing extents, whether by a form of pentatonic scale or the scale common to Klezmer, arabic, Indian music, etc. Or perhaps by other means like tuning or rhythm.
Is there a 'family tree' similar to what we have for language that attempts to trace the historical lineage of different people's folk music?