Once a boy was castrated he would go to a special music school where children learned singing and musical instruments. The castrati pupils were given special treatment. They were fussed over and kept warm to stop them from getting colds. When they grew up they hoped to become famous opera singers. A few of them had very successful careers in opera. They were the great stars of their day, and audiences came to the opera to cheer on their favourite singers. Those who were not good enough to make a career in opera joined church choirs instead.