Casaer was played by a woman ( the part was written for a castrato , except they do n't castrate people anymore , so they have to use women instead ) , which was interesting to see . Also , there was a fairly small ensemble accompanying the singers , so there were no walls of sounds or great impressive fanfares . But the music was good .
According to the above context, choose the best option to answer the following question.
Question: What may I have just seen ?
Options:
- A rock show
 - A opera
 - None of the above choices .
 - A play


A opera