Set up the grill for direct grilling and preheat to high. Strip back the husk, starting at the top of the ear of corn; the motion is rather like that of peeling a banana. Leave husk attached to the steam end. Remove corn silk and fold the husk back over the stalk. Tie the husk with string to form a handle. Place the butter, parsley, and garlic in a mixing bowl and whisk or beat until smooth and creamy. When ready to cook, lightly brush each ear of corn with a little of the garlic-parsley butter and arrange on the hot grate, positioning the ears in such a way that the husks are away from the fire or slide a sheet of aluminum foil under them. Grill the corn until the kernels are handsomely browned all over, 8 to 12 minutes in all, turning as needed, brushing with the remaining butter and seasoning generously with salt and pepper. Remove the corn from the grill and serve at once.