Writer David Hajdu is the author of the new book, Positively 4th Street: The Lives and Times of Joan Baez, Bob Dylan, Mimi Baez Farina, and Richard Farina. (Farrar, Strauss & Giroux). The book focuses on the early 1960s when the four of them changed the nature of popular music. Hajdu is also the author of the award-winning biography, Lush Life: A Biography of Billy Strayhorn. Hajdu also writes for The New York Times Magazine, and Vanity Fair.