Reckoning with the Dead at the Sphere

In May, I came across an ad in the subway promoting the months-long residency at the Sphere, in Las Vegas, of Dead & Company, the current permutation of the Grateful Dead, featuring two surviving members, Bob Weir and Mickey Hart, and the pop star John Mayer. The ad read, in a brassy “Star Wars” font, “Dead Forever.” I remembered what David Letterman said years ago when he saw a billboard in Times Square for the musical “Cats”: “ ‘Cats: Now and Forever’—is that a threat?”