* TheCastShowoff: The bronze {{sculpture|s}} of Christine Dubois (Susanna Foster) was actually made by co-star Nelson Eddy, who was an accomplished {{sculptor|s}}.
* DyeingForYourArt: Nelson Eddy's hair was to be dyed black because of script requirements for his role of operatic baritone Anatole, maybe intending to refer to Norman Kerry looks in the silent version. Nelson only agreed when Jack Pierce developed a one-day tinting that could be washed out after each day's shooting, allowing Nelson (who was of Dutch ancestry) to recover his characteristic blond hair.
* ExecutiveMeddling: The original screenplay of the 1943 version revealed that Erique was Christine's father. But the execs at Universal were afraid that viewers would think the relationship between Christine and The Phantom had [[{{Squick}} incestuous overtones]], so that revelation was cut out.
** Incidentally, it's entirely possible to watch the movie with this in mind, and it makes just as much sense as the canonical unrequited-love plot (since Erique's interest in Christine, unlike his counterparts in other versions, ''is'' more of an ambiguous deep concern for her that could go either way).
* MidDevelopmentGenreShift: The film was initially conceived to be a part of the ''Creator/AbbottAndCostello'' series, with Creator/LonChaneyJr as The Phantom.
* RecycledSet: The auditorium and stage of the Paris Opera House seen here was the same set built for the 1925 version. It still stands at Universal Studios today as Stage 28, and has been used for countless other productions. It is the oldest remaining film set in the world and rumored to be haunted.
* SavedFromDevelopmentHell: Creator/{{Universal}} first announced a remake of ''Film/ThePhantomOfTheOpera1925'' in 1935. This version would have been set in contemporary Paris, and would have portrayed the Phantom as a psychologically wounded World War I veteran who was physically unharmed, but imagined that he was disfigured.
* StillbornFranchise: A sequel named ''The Climax'' was planned, but the plans fell through due to unavailability of Creator/ClaudeRains, among other problems. The film was eventually made as ''Film/TheClimax''.
* WagTheDirector: Creator/ClaudeRains accepted to play the Phantom under the condition that no overdone disfiguration would be made. Jack Pierce succeeded in fulfilling his requirement, according to the documentary included in the DVD release.
* WhatCouldHaveBeen: Creator/BorisKarloff, Creator/CharlesLaughton and Creator/CesarRomero were considered for the Phantom.
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