The gigantism of Wagner—the sheer scale of his output, his stupendous intellectual scope, his action-packed life, and his all but unfathomable personality—affects the works that have been written about him, and Alex Ross’s book, about his influence, past and present, is a real doorstopper. But it could not have been a page shorter. Wagner’s reach, as Ross comprehensively demonstrates, is vast, greater by far than that of any other musician in history, greater perhaps than any artist in any medium, his influence profound and continuing and by no means confined to music itself. I find myself already slipping into ...