Carlo Maria Broschi, better known as Farinelli, was one of the most celebrated opera singers of all time, and the 18th century equivalent of a rock star ("One God and one Farinelli," one lady cried out after he'd finished an aria). Handel courted him for years. Mozart sought him out. His voice was extraordinary in every way. On the other hand, he had no testicles after the age of 12. And his skull was much thicker about the forehead than a typical human being's. According to this paper, published in the Journal of Anatomy this month, all of these facts are related.
Castration before puberty preserves the small vocal cords of a boy, even as the head and body grow to full size. The result was, apparently, an amazing sound, unlike anything we know today. You can get a faint idea of the tone listening to this recording of the only castrato to have been recorded, at the dawn of the last century. Or you can sample this digital reconstruction, by David Howard, for a BBC documentary (at around 4:25 on the video) . Or there's another digital approximation, in Gérard Corbiau's Farinelli biopic (made by combining male and female renditions of each aria).
For those who could really hear it in its prime, the castrato voice was "as clear and penetrating as that of choirboys but a great deal louder with something dry and sour about it yet brilliant, light, full of impact," said a contemporary critic (quoted in this thorough Lancet article, which is a must-read if you're planning to castrate someone for musical purposes).
Hence, castrati were treasured in European music through the 16th, 17th and 18th centuries. "Evviva il coltellino!" (long live the little knife!) fans would cry to the castrato stars (though, as Jan Swafford notes here, for every star success there were thousands of wannabes who led pretty wretched lives. These men truly had no choice but "artist or nothing.") Even though the procedure was against the law by the time Farinelli underwent it in 1717, there were apparently doctors-of-convenience who supplied the needed letters—he supposedly fell from a horse, wink wink.
Five years ago, physical anthropologists exhumed Farinelli's remains in Bologna as part of a project to glean information about the medical, social and physical state of 18th-century Europeans. The new paper reports on some anomalies in Farinelli's skull and skeleton, some of which weren't too surprising. Not having gone through puberty, the bones of castrati did not fuse, so they were tall. Farinelli's limb bones turned out to be quite long. A more surprising find was that the skull showed severe hyperostosis frontalis interna (HFI)—the thickening of bone behind the forehead. It's much more common in women than in men, and that's one reason that the authors suspect Farinelli's condition was a consequence of his castration.
There seems to be some disagreement about whether HFI has consequences for daily life. Some speculate that it can lead to terrible headaches, and this study found a substantial number of HFI cases among mental patients. But it doesn't seem to be clear that this is due to a cause-and-effect relationship, rather than the fact that HFI was most often studied in mental patients.
Castrati were often stereotyped as mentally unstable, and many living HFI cases have suffered from dementia and depression and paranoia. On the other hand, people say the same about all opera singers. Farinelli was said to have led a melancholy existence. You could argue, though, that he had other reasons for sorrow than pressure from the bones in his skull.
Illustration: Farinelli, portrait by Jacopo Amigoni, via Wikimedia.
Giovanna, B., Antonio, T., Gino, F., & Valentina, M. (2011). Hyperostosis frontalis interna (HFI) and castration: the case of the famous singer Farinelli (1705-1782) Journal of Anatomy DOI: 10.1111/j.1469-7580.2011.01413.x