A Midsummer Night's Dream 5.1.046 Eunuch

The transcript discusses the role of eunuchs in ancient kingdoms, where they served as guards for harems due to the belief that they would not engage with the women. It also highlights another type of eunuch, young boys castrated before puberty to maintain a high singing voice, as referenced by Philistrate.

How did the castration of young boys affect their singing abilities?

Who is Philistrate, and what is his connection to the eunuchs mentioned?