Cooks' note:
Corn can be cooked 6 hours ahead and chilled, covered (without scallion or bacon). Reheat in skillet or a 4-quart heavy saucepan over moderate heat, stirring occasionally, then stir in scallion and salt and pepper to taste. Bacon can be kept at room temperature, then reheated on a small baking sheet in a preheated 400°F oven until hot, about 2 minutes.