“For every superstar castrato who graced Europe’s opera houses between about 1600 and 1828 (when Giovanni Battista Velluti became the last eunuch to appear on stage, in a crusader epic by Meyerbeer), there were hundreds whose ordinariness or unpleasantness of voice condemned them to a life in B-grade church choirs, or on the streets as beggars or prostitutes. And those were the ones who survived the operation…”