The most influential musician to emerge out of the social unrest of the early 1960s, Bob Dylan dramatically expanded the aesthetic and political boundaries of popular song. Recognized almost immediately as the voice of his generation, Dylan began his brilliant career by performing blues, folk ballads, and his own topical compositions, many of which addressed issues of racial injustice and protested against the threat of nuclear war. By 1965 he transformed himself into a rock star, the first of many metamorphoses he would undergo over the next three decades. Mercurial, iconoclastic, and enigmatic, Dylan variously presented himself as a poet, gospel singer, bluesman, country musician, and minstrel, recording more than thirty albums that would make him one of the major popular artists of the twentieth century.

"Dylan has invented himself. He's made himself up from scratch," wrote playwright Sam Shepard. The point, Shepard suggested, "isn't...