Leroux often uses metaphor to dramatize climactic scenes. In Chapter 8, when Carlotta begins to sing in an ugly tone, the narrator uses a metaphor to compare her voice to a toad:
For her harmonious voice – that agile instrument which had never failed her; that magnificent organ which could create the most beautiful sounds and deliver the most demanding melodies [...] – had just produced … For her very mouth had just produced … a toad! And what an awful, hideous, scummy, slimy, venomous, hoarse toad it was!
Here, the narrator describes the awful croaking noise in Carlotta's throat as a toad. Carlotta has fallen under the Phantom's spell and continues to sing despite the drastic change in her voice. The audience erupts into horrified shrieks, chaos ensues, and finally, the chandelier comes crashing down. After this initial description, the narrator makes it very clear that the toad is metaphorical:
How did it come to crouch on her tongue, with its hind legs folded so as to spring higher and further? It had surreptitiously issued from her larynx and … croak! Croak! Croak! Oh! What a dreadful sound! The toad in question was, of course, a metaphorical one. It could not be seen, but, in Hell’s name, it could be heard! [...] Never was such a raucous croak heard, by the side of a noisy pond, ripping through the nocturnal air.
The way the narrator presents this metaphor makes him seem very self-aware and erudite. His repetitive emphasis on the toad-like quality of Carlotta's voice ensures that readers know how awful it sounds. Words like "raucous" and "ripping" enhance the power of this memorable metaphor by creating contrast with initial descriptors like "harmonious" and "agile"; this contrast subtly evokes the interplay of beauty and ugliness throughout the novel.
The most prominent example of imagery in The Phantom of the Opera is, of course, auditory. In Chapter 10 the narrator describes the Phantom's voice in great detail:
The disembodied voice resumed singing. Never in his life had Raoul heard a voice combining in one breath such extremes, a voice at once immensely, heroically sweet and triumphantly insidious, subtly powerful and powerfully subtle, in short a voice of irresistible potency. There was, in that singing, something definitive and masterful that must, in itself, inspire every mortal who appreciates, loves and makes music. It was a tranquil and pure fountain of harmony from which the faithful could safely and piously assuage their thirst, secure in the knowledge that they were partaking of musical grace.
Words like "heroically sweet" and "subtly powerful" form a well-rounded depiction of the Phantom's voice. The repetitive interplay of opposites, as well as the metaphorical "fountain of harmony" to which his voice is compared, show a range of rhetorical techniques comparable to the Phantom's range of singing talent. Whether or not this is intentional remains unclear; however, the narrator's extensive research and sympathy toward the musically-gifted Erik suggest that the story's form purposefully matches its content. Finally, it is important to note that the Phantom's music often appears to have holy qualities despite his violent and immoral tendencies.
In Chapter 13, Christine tries to describe the indescribable voice of the Phantom. She uses a simile that compares his voice to that of an angel:
I could not hear the voice outside my door, whereas inside the singing continued. And not only did the voice sing, it also spoke to me: it answered my questions, like the voice of a real man, with this difference: it was as beautiful as an angel’s voice. How could I explain so unbelievable a phenomenon?
There are two similes here: "like the voice of a real man" and "as beautiful as an angel's voice." Christine cannot concisely capture the Phantom's voice in mere words; he walks the line between man and angel because he can speak but also has an unspeakably beautiful voice. In fact, Christine believes that Erik might have been an angel if not for his terribly disfigured face. Her two similes demonstrate how the Phantom straddles the line between human and angel and recall the novel's recurring juxtaposition of the natural and the supernatural. Christine's comparison of his voice to that of an angel serves as a reminder of his mysterious, otherworldly talent.
In Chapter 10, the narrator describes Raoul's reaction to the Phantom's voice in a similar way:
It was a tranquil and pure fountain of harmony from which the faithful could safely and piously assuage their thirst, secure in the knowledge that they were partaking of musical grace. Having touched the Divine, their art was transfigured.
The metaphor of a "fountain of harmony" evokes the endless, effortless beauty with which Erik sings. Words like "pure," "faithful," "piously," and "Divine" clearly have religious connotations that match the Phantom's nickname "Angel of Music" and recall Christine's apt simile. Although Raoul is loath to admit Erik's talent, he must recognize the beauty of his voice.
Erik resents his compulsory mask-wearing, but he is far less masked than the other metaphorically-masked characters. One example of masked feelings includes Christine's bogus engagement to Raoul. In Chapter 12, Christine suggests a "secret marriage" that will last only one month:
"But if we cannot be married, we can become engaged! No one but us will know. There have been plenty of secret marriages! Why not a secret betrothal? Let us become engaged, Raoul, for a month! In a month’s time, you will sail away and the memory of that month will keep me happy for the rest of my days!" She was overjoyed by this prospect. Then she became serious again and added: "This happiness will hurt no one."
Here, Christine claims that the mere memory of their month-long engagement will keep her happy for the rest of her life. Her invention of a bogus union is her attempt to mask the unhappy confusion of being trapped by the Phantom. She and Raoul merely "play" at being husband-and-wife-to-be in a "beautiful game" that serves to cover her sadness for a little while.
Other examples of metaphorical masking include Christine and Raoul's many attempts to deceive Erik and the Persian's lies about why he comes to the opera. By contrast, Erik's mask eventually comes off, leaving him vulnerable to Christine, who receives him with unexpected warmth. This decision to unmask makes Erik the least hidden and most vulnerable character in the book. Masks appear as a significant metaphor for the hiddenness of identity and motive; the irony of Erik's compulsory mask emerges as the other characters' tendencies to mask their true desires or feelings become apparent. Throughout the story, this irony depends on the device of masking as an extended metaphor for concealment.
In Chapter 13, Christine tries to describe the indescribable voice of the Phantom. She uses a simile that compares his voice to that of an angel:
I could not hear the voice outside my door, whereas inside the singing continued. And not only did the voice sing, it also spoke to me: it answered my questions, like the voice of a real man, with this difference: it was as beautiful as an angel’s voice. How could I explain so unbelievable a phenomenon?
There are two similes here: "like the voice of a real man" and "as beautiful as an angel's voice." Christine cannot concisely capture the Phantom's voice in mere words; he walks the line between man and angel because he can speak but also has an unspeakably beautiful voice. In fact, Christine believes that Erik might have been an angel if not for his terribly disfigured face. Her two similes demonstrate how the Phantom straddles the line between human and angel and recall the novel's recurring juxtaposition of the natural and the supernatural. Christine's comparison of his voice to that of an angel serves as a reminder of his mysterious, otherworldly talent.
In Chapter 10, the narrator describes Raoul's reaction to the Phantom's voice in a similar way:
It was a tranquil and pure fountain of harmony from which the faithful could safely and piously assuage their thirst, secure in the knowledge that they were partaking of musical grace. Having touched the Divine, their art was transfigured.
The metaphor of a "fountain of harmony" evokes the endless, effortless beauty with which Erik sings. Words like "pure," "faithful," "piously," and "Divine" clearly have religious connotations that match the Phantom's nickname "Angel of Music" and recall Christine's apt simile. Although Raoul is loath to admit Erik's talent, he must recognize the beauty of his voice.
After Carlotta's fatal performance, Christine begs the Phantom to reveal himself to her. She fears that he was killed by the falling chandelier and desires to know if he is still alive. The name Lazarus appears in Chapter 13 in her plea as an allusive metaphor:
The Voice did not reply, but suddenly I heard a long, exquisite lament, which I knew well. It was the plaint of Lazarus when, at the sound of Jesus’ voice, he begins to open his eyes and see the light of day. It was my father’s violin weeping; I even recognized his bowing stroke. It was the sound that made us, you and me, stop in our tracks as children – the sound that cast its spell over the graveyard that night at Perros. The invisible, triumphant violin played again the joyous cry of Life and at long last I heard the overwhelming, sovereign call of the Voice singing the words: “Come! And believe in me! He that believeth in me, though he were dead, yet shall he live!"
The quote within the quote above ("He that believeth in me...") is from the Gospel of John where it's spoken by Jesus just before the raising of Lazarus, and the words "sovereign call" suggest that the sung quote identifies the Phantom's voice with that of Jesus.
In addition to the biblical figure Lazarus, the novel also refers to the piece Lazarus that Christine's father used to play. According to the Bible, Lazarus rose from the dead; and the song her father played symbolized the potential for hope and redemption. This allusion suggests that the Phantom, like Lazarus, is still alive, and Christine is relieved and frightened by this thought at the same time.
