Ryan Adams' signature mix of classic country, folk tradition, and hard rockin' draws from many canonical sources. You can hear how Gram Parsons' twang in songs like “Streets of Baltimore” directed Adams' down-home style and find the all-American muscle of Springsteen's “Prove It All Night” in Adams' mid-'10s albums. But he's a punk at heart, and Black Flag's “Nervous Breakdown” was the incendiary impetus for his thrashiest work.