Music and Culture Question

I'm currently studying "American Culture" and get to write one essay in my exam on any aspect in which I have an interest.  For my un-assessed essay I wrote about hip-hop but in the exam I was hoping to write about how Steve Earle etc write about American memory/geography/technology (the memory/geography/technology thing is the "hook" of the module).  Anyway, though I want to do my own research, I was wondering if there were any sources you could point me to, internet is fine for this one, so links appreciated too!