What tells more truth than the distant whistle of a passing freight train on a drizzly Monday morning? Nothing. Not the scratchy recordings of Édith Piaf singing “La Vie en rose.” Not Linda Loman’s summing up of the life of her husband Willie. Not Vonnegut or the Adagio for Strings or any particular twelve-bar blues. The train whistle is their equal, a mechanical maestro of the bittersweet.