Recently in one of my classes we watched the opera Giulio Cesare by Handel. This was a very long opera. One of the interesting things about it is that were three parts in this opera written for castratos. All three of these parts were played by counter tenors in the production that we watched. Cesare was one of these parts, and it was very strange to how regal he looked and know what a strong character he was supposed to be and then hear him sing in such a small, high voice. It is quite unfortunate that we will never be able to hear what this part would have sounded like with the full strength of a castrato's voice behind it (not that it is in any way unfortunate that such barbaric customs no longer exist). The counter tenor voice fit Ptolemy much better because he is a much weaker character.
I loved listening to Cleopatra whenever she sang. She had a beautiful voice and an engaging stage presence. I also loved her character because when things weren't going her way, she stand up for herself instead of sing long whiney arias. I also greatly enjoyed watching and listening to Cesare once I had adjusted to his voice. My favorite part was when there was a break from the plot of the opera while had a musical duel against a violinist.
There were, however, some less than enjoyable parts to this three hour opera. Cornelia was the most ridiculous character because all she did was despair and try to kill herself throughout the entire opera. Her son Sextus, written for and played by a woman, was also ridiculous because he would sing long arias about how he was going to kill Ptolemy, but every time he got near him, he would somehow manage to mess it up. I don't know if this character bothered me so much because he was so stupid or because the singer who played him was so incredibly bad a playing a man. I'm sure her voice was very lovely, but I couldn't concentrate on her singing at all because I was too busy being frustrated with what I was watching. If I had been listening to a recording, my reaction to this particular person probably would have been completely different.