A prisoner who was scheduled to be executed soon saw the king with his horse through his cell window and decided to send the king a message. The message said, "Your Royal Highness, if you will spare my life, and let me spend an hour each day with your favorite horse for a year, I will teach your horse to sing."
The king was amused by the offer and granted the request. So, each day the prisoner would be taken from his cell to the horse's paddock, and he would sing to the horse "La-la-la-la" and would feed the horse sugar and carrots and oats, and the horse would neigh. And, all the guards would laugh at him for being so foolish.
One day, one of the guards, who had become somewhat friendly with the prisoner, asked him, "Why do you do such a foolish thing every day singing to the horse, and letting everyone laugh at you? You know you can't teach a horse to sing. The year will pass, the horse will not sing, and the king will execute you."
The prisoner replied, "A year is a long time. Anything can happen.
In a year the king may die. Or I may die. Or the horse may die.
Or ...
The horse may learn to sing. "