I've recently discovered Vitas, on youtube. His voice fascinates me…
He sings both classical music and pop (this video, for instance, not classical, is rather funny:
http://fr.youtube.com/watch?v=ygJYxM...elated&search= )

As for castratis, i had the chance to hear one, many years ago: A priest of my parish, native of India, sang a traditional song. He was not only a countertenor, because his voice was so light, so wonderful, … but he still had his voice of child. Marvelous…