Mix lemonade concentrate and water in a small bowl. Pour over chicken in larger bowl. Refrigerate 2 hours or longer. Drain chicken and reserve liquid. Mix together the flour, salt, and pepper in a small paper bag. Add well-drained chicken, one piece at a time, and shake to coat evenly. Heat oil in large skillet over moderate heat. Add floured chicken; cook until evenly browned, turning pieces over carefully. Remove chicken and arrange in a single layer in a shallow baking pan. Brush chicken with melted butter; add reserved lemonade. Bake in preheated 350-degree oven uncovered about 1 hour, basting chicken with lemonade from pan every 15 minutes. About 15 minutes before chicken is done, drain off excess juice from pan. Serve hot.