It’s not often the universe tells you to pay attention to Italian opera. Okay, maybe never. But today it did, twice. In the novel I’m reading, “My Grandmother Asked Me to Tell You She’s Sorry,” by Fredrik Backman, 7-year-old Elsa gets into her friend Alf’s cab, and he’s listening to Italian opera. And this afternoon, David Johansen plays this piece by Maria Callas, a Greek opera singer who became famous in Italy, and whose life was marked by struggles, scandal and personal tragedy.