This extraordinary book is truly a group effort, even though the author might have actually preferred it had never been published. Obsessed with the obscure blues giant Robert Johnson, Robert “Mack” McCormick spent years systematically tracking Johnson’s traces across the Mississippi-Texas-Oklahoma landscape, following every tiny lead to ground. The research was essentially complete in 1970, but mental illness and lack of money made it impossible for the author to complete a publishable manuscript in his lifetime. What we have here, as the Smithsonian editor describes it, is a highly edited version of his final manuscript, even down to removing all traces of Johnson’s two sisters, who asked to be removed from the book after they felt taken advantage of by McCormick. Editor John W. Troutman is clear about the delicate racial politics of McCormick’s project, as a white journalist whose sources were all Southern Black people just after the height of the Civil Rights era; Troutman’s foreword might be a bit heavy-handed since McCormick himself was aware of the need for tact and diplomacy in his fieldwork, even if his single-mindedness sometimes got in the way of that politesse. But in the climactic chapter, when he finds himself in the right place with the right people, no one can dispute his ability to bring to life the transformative power of the music and its link to the Mississippi Delta. Some of those scenes are magical, and whatever McCormick’s flaws, you can’t take that away from him.