“Over the past year, it's become fashionable to add the twitter and jasmine of 1970s folk to the tastemaker's stew. Sure, that sound has always been around, kept alive in both the thriving cult of Nick Drake and by the dudes who get into Tim Buckley because the hottest girl they ever knew loved his kid's voice. But if the folk trend started in earnest late last year with the homey, kitchen-sink ram”