It is quite simple, actually. Imagine you are standing in the midst of a lightly treed wood. If you have never had the opportunity to leave the inner city or to find an escape from your suburban hellhole, I am sorry; use this picture as a visual aid.
So, as you can see in this illustrative illustration, there is a cute lil' creek set between some trees and mud and probably some organisms that like to suck people's blood. Now aren't you glad you stayed in suburbia? Anyway, that creek is the Mainstream. The Mainstream is populated by the larger rocks at the bottom that often stay put but are sometimes moved along bit by bit, clunk, clunk, clunk, and by the smaller sediments that are carried along by the water. These small sediments are Elitists. They are an essential part of the Mainstream, but, importantly, they also view themselves as distinct from the comparatively unmoving Middle America rocks that stick to the stream bed. The Elitist sediments and Middle America rocks disdain one another for being uppity and traditionalist, respectively, but they both appreciate Glee.
Now, climbing up one of the banks of the Mainstream, you can spot in the distance another, decidedly smaller stream. It twists and turns on its way to some estuary, as tends to happen with such bodies of water, but it does so ironically. This, after all, is Hipster River. Hipster River is too small to contain the diverse rock types we see in the Mainstream; all you can find here are water-smoothed pebbles wearing lensless glasses, a few scattered Sufjan Stevens CDs (a CD--it's like a flat metal bagel), and Asiya.
