Code Geass R2

If anyone is still wondering.
http://en.wikipedia.org/wiki/Eunuch

here's the answer for the small voice:

In Europe, when women were not permitted to sing in church or cathedral choirs in the Roman Catholic Church, boys were sometimes castrated to prevent their voices breaking at puberty and to develop a special high voice. The first documents mentioning castrati are Italian church records from the 1550s.In the baroque music era these singers were highly appreciated by Opera composers as well. Famous castrati include Farinelli, Senesino, Carestini, and Caffarelli. Joseph Haydn was almost castrated. The last castrato was Alessandro Moreschi (1858-1922) who served in the Sistine Chapel Choir. However, in the late 1800s, the Roman Catholic Church, which had always considered castration to be mutilation of the body and therefore a severe sin, condemned the production of castrati; their castrations had been performed clandestinely in contravention of Church law.
Source: Wikipedia