King Louis XI
of France was a sick puppy
who also had a fascination with the animal
kingdom. Sometimes he managed to combine his cruelty
with his love for animals, such as organized manhunts
in which victims were covered with deer
skin, and then chased and torn to bits by hounds
The Pig Organ was another such combination of Louis' two loves. 17th-century writer Nathaniel Wanley describes it better than I ever could:
"The Abbot of Baigne, a man of great wit, and who had the art of inventing new musical instruments, being in the service of Louis XI, king of France, was ordered by that prince to get him a concert of swine's voices, thinking it impossible. The abbot was not surprised, but asked for money for the performance, which was immediately delivered him; and he wrought a thing as singular as ever was seen. For out of a great number of hogs, of several ages, which he got together, and placed under a tent or pavillion, covered with velvet, before which he had a table of wood, painted, with a certain number of hogs, he made an organical instrument, and as he played upon the said keys, with little spikes which pricked the hogs he made them cry in such order and consonance, as highly delighted the king and all his company."
In the mid-19th century, this idea was resurrected by the inventor of the so-called Porco-Forte instrument, which pinched the tails of pigs to elicit their squeals.