Gaston Leroux
There have been many published novels based on 'Le Fantôme de l'Opéra' which was written by Gaston Leroux, but no-one can call themselves a phan unless they have read the original novel.
For those who don't own a copy, but would like to read it, you can download the english version.
Gaston Leroux introduces the story by saying:
"The opera ghost really existed. He was not, as long believed, a creature of the imagination of the artists, the superstition of the managers, or a product of the absurd and impressionable brains of the young ladies of the ballet, their mothers, the box-keepers, the cloak room attendants or the concierge. Yes, he existed in flesh and blood, although he assumed the complete appearance of a real phantom; that is to say, of a spectral shade."
He based the story in a real opera house in Paris, which can still be visited today. The chandelier still hangs above stage, and box five can also be seen.
Gaston Leroux is also author of:
The mystery of the yellow room:
and
The perfume of the lady in black