How did a middle-class Jewish boy from a small town in northern Minnesota become the heir to Woody Guthrie, the working class Oklahoma balladeer? How did a high school rock 'n' roller who worshiped Little Richard become the defining voice of the folk revival? Why do historians treat a brief, three-song electric set at the Newport Folk Festival as a seismic shift in American music and culture? And how did all of that turn into a hit movie?

Elijah Wald is a musician, writer, and historian. He was the Boston Globe's world and roots music writer for much of the 1980s and 1990s and has written over a dozen books, including Dave Van Ronk's memoir "The Mayor of MacDougal Street" (which inspired the Coen Brothers' "Inside Llewyn Davis"), "How the Beatles Destroyed Rock 'n' Roll: An Alternative History of American Popular Music," and "Dylan Goes Electric!" (which inspired the recent movie, "A Complete Unknown").