opera is woven with a surprisingly transgressive relationship to gender. Mozart, Strauss, and Verdi all wrote "trouser roles" or "pants roles," male characters explicitly created to be played by women; the earliest known operas had female sopranos in the roles of boys.
Castrati, men who were castrated before puberty in order to preserve their high voices, were celebrated, considered superstars of their time, and played both male and female roles.Despite all of that, when it comes to opera singers who are out and identify as trans, there are few who've made it.