Revelatory ... Shines when it offers glimpses into the lives of Schuyler’s luminous pals ... Throughout this book, which is rich with original interviews, Mr. Kernan offers sensitive readings of Schuyler’s poems and moods ... Mr. Kernan and Schuyler became good friends in 1990, the year before Schuyler died, and it feels oddly appropriate when, toward the book’s conclusion, its author starts popping up in its pages.