Phantom- Croak

  Thenceforth, certain of herself, certain of her friends in the house, certain of her voice and her success, fearing nothing, Carlotta flung herself into her part without restraint of modesty … She was no longer Margarita, she was Carmen. She was applauded all the more; and her debut with Faust seemed about to bring her a new success, when suddenly … a terrible thing happened.
...

  With its melody enwind me

  And all my heart subdue.”

  At that moment, at that identical moment, the terrible thing happened … Carlotta croaked like a toad:
  “Co-ack!”
  There was consternation on Carlotta’s face and consternation on the faces of all the audience. The two managers in their box could not suppress an exclamation of horror. Every one felt that the thing was not natural, that there was witchcraft behind it. That toad smelt of brimstone. Poor, wretched, despairing, crushed Carlotta!
...
  No, Carlotta did not go on … Bravely, heroically, she started afresh on the fatal line at the end of which the toad had appeared.
  An awful silence succeeded the uproar. Carlotta’s voice alone once more filled the resounding house:

  “I feel without alarm …”

  The audience also felt, but not without alarm …

  “I feel without alarm …

  I feel without alarm—co-ack!

  With its melody enwind me—co-ack!

  And all my heart sub—co-ack!”

  The toad also had started afresh!
  The house broke into a wild tumult. The two managers collapsed in their chairs and dared not even turn round; they had not the strength; the ghost was chuckling behind their backs!

-Chapter VII