Dylan, who began working on the book in 2010, offers his extraordinary insight into the nature of popular music. He writes over sixty essays focusing on songs by other artists, spanning from Stephen Foster to Elvis Costello, and in between ranging from Hank Williams to Nina Simone. He analyzes what he calls the trap of easy rhymes, breaks down how the addition of a single syllable can diminish a song, and even explains how bluegrass relates to heavy metal.