" Then I saw the keyboard of an organ which filled one whole side of the walls. On the desk was a music-book covered with red notes. I asked leave to look at it and read, ‘Don Juan Triumphant.’ ‘Yes,’ he said, 'I compose sometimes.’ I began that work twenty years ago. When I have finished, I shall take it away with me in that coffin and never wake up again.’ 'You must work at it as seldom as you can,’ I said. He replied, 'I sometimes work at it for fourteen days and nights together, during which I live on music only, and then I rest for years at a time.’ 'Will you play me something out of your Don Juan Triumphant?’ I asked, thinking to please him. 'You must never ask me that,’ he said, in a gloomy voice. 'I will play you Mozart, if you like, which will only make you weep; but my Don Juan, Christine, burns; and yet he is not struck by fire from Heaven.’ Thereupon we returned to the drawing-room. I noticed that there was no mirror in the whole apartment. I was going to remark upon this, but Erik had already sat down to the piano. He said, 'You see, Christine, there is some music that is so terrible that it consumes all those who approach it. Fortunately, you have not come to that music yet, for you would lose all your pretty coloring and nobody would know you when you returned to Paris. Let us sing something from the Opera, Christine Daae.’ He spoke these last words as though he were flinging an insult at me.”

“What did you do?”

“I had no time to think about the meaning he put into his words. We at once began the duet in Othello and already the catastrophe was upon us. I sang Desdemona with a despair, a terror which I had never displayed before. As for him, his voice thundered forth his revengeful soul at every note. Love, jealousy, hatred, burst out around us in harrowing cries. Erik’s black mask made me think of the natural mask of the Moor of Venice. He was Othello himself. Suddenly, I felt a need to see beneath the mask. I wanted to know the FACE of the voice, and, with a movement which I was utterly unable to control, swiftly my fingers tore away the mask. Oh, horror, horror, horror!”

Christine stopped, at the thought of the vision that had scared her, while the echoes of the night, which had repeated the name of Erik, now thrice moaned the cry:

“Horror! … Horror! … Horror! "

― Gaston Leroux , The Phantom of the Opera