In 1967, Leonard Cohen released “So Long, Marianne,” a requiem for a love affair that was unravelling, or at least transforming in some critical way. The song is romantic—the Marianne of its title was Cohen’s girlfriend and muse in the nineteen-sixties—but its fourth verse contains what I’ve always thought was a profound articulation of grief: I listened to “So Long, Marianne” dozens, possibly hun...