I scanned the first page from each chapter from the Piotr Scholz book. Also here is a current day male singer with a high voice, his name is Filippo Mineccia. He is singing from the baroque composer Francesco Gasparini. It isn't right to castrate boys, but shit happens. Also from that time period if families have 14 kids, and two survive, then if one boy is castrated and becomes the equivalent of a multi-millionaire, then that could lift a family out of poverty.
https://www.youtube.com/watch?v=r_CdVUA5j_k&t=599s