A beautiful voice, what does that mean? When you have to interpret a role you have to have thousands of colours during the performance to portray the words you do. Happiness, joy, unhappiness, sorrow, fear- how can you just have a beautiful voice period? You must put that to the service of expression. So therefore even if you have to sing harshly sometimes, (which I frequently have done), shrill, it is a necessity of expression. It is written there, you have to respect the words and you have to do it even if people will not understand- but on the long road they will!
Maria Callas