It's possible, even probable, that no one has the depth of knowledge about rock 'n' roll history that Richie Unterberger has. His 40+ year career, starting as a DJ in college to writing 15 books, countless reviews and articles, has focused on the music of the 60s and 70s. This episode focuses on his new books about the Velvet Underground and The Who and looks back at how rock music has changed over the decades.