It seems to me that in any country, in any culture, there are two basic kinds of popular music. First, there is commercially generated music, which flows forth on radio waves and is transmitted into people’s lives through screens, magazines, and other two-dimensional things. It is the most easily recognizable face of music in a society, a face that winks at us all with the eyes of pop divas, and sneers at us with the lips of rock stars.
However, beneath the surface of mainstream popular culture, there is the ever-present undercurrent of organically generated music. This other branch finds its sources much further back than its mass-marketed contemporaries, and is comprised (in America anyway) of a seemingly endless system of interconnected musical tributaries and little regional inlets.
While these two basic forms are not mutually exclusive, and often overlap, the latter is generally born of a particular and specific community or individual expression, and manifests itself not as a commodity, but as a social activity.
– From Ani Difranco’s Preface to Elijah Wald and John Junkerman’s River of Song: A Musical Journey Down the Mississippi. St. Martin’s Press, New York, 1998