Disclaimer: I don't own anything and make no money… Etcetera, etcetera, etcetera.
AN: This little vignette is based upon the 1990 TV miniseries, which is in turn based on the Maury/Yeston musical. Here, Christine is making her debut at an opera company gathering instead of in an operatic gala, and the Phantom waits outside, much as he did below in ALW's version, to hear her sing. In either case, his thoughts may have been very similar.
Par le rang et par l'opulence is an aria from Donizetti's La Fille du Regiment (The Daughter of the Regiment), and in the miniseries, this is what Christine sings as her debut.

"For I am blackness itself, aren't I?"
Erik, the Phantom of the Opera
I shouldn't be here.

My heart is pounding, and I feel rather lightheaded, which almost makes me laugh. I haven't been this worked up in a very long time. In fact, I can't remember the last occasion I had cause to be so nervous. Wait, no, there was a time - not so terribly long ago, actually. When I spoke to Christine, shakily asked her if she would like singing lessons, and then vanished into the depths beneath the stage. I'd had to sit down and breathe deeply for a good while after that initial encounter. What perfection she is, balanced against my monstrousness.

I was supremely foolish to come, to stand here at the corner of the bistro stairs, in the vain hope that I would hear my protégé, my angel, my Christine, in her triumphant debut. For she would be triumphant, I had no doubt, as long as her own nerves did not give way.

Laughter, music, and conversation flow down to me from the upstairs establishment, and for a brief moment, I wonder what it would be like to be among the company now. To enjoy the music and the camaraderie with a free conscience and an unmasked face, relishing in the unthinkable delight of having Christine see – and love – me, not as her maestro, but as a man. I scoff, rolling my eyes. What folly.

And suddenly there it is, the purity of Christine's angelic voice, rising over the clink of glasses and the burbling murmur of humanity. Oh, quiet, you fools, don't you realize what divinity has come among you for the evening? She is doing very well from what I can hear – her voice properly placed and supported, just as I taught her. I chose Par le rang et par l'opulence from among her repertoire as the one aria that best displays her talent – soaring passages that descend without accompaniment, allowing her perfect tone to float, haunting, sending chills up the spine of he who would hear.

They have fallen silent now, the members of this opera company, properly astonished and amazed at her hitherto unsuspected virtuosity – perhaps seeing her now in a very different light, as one to respect.

And then a new voice joins in, obscuring Christine, as startling and jarring in its wild vibrato and horrible intonation as hers is unblemished. I clench my fist. Carlotta. What an idiot I was to think this so-called diva would simply allow her lowly costume girl to sing and upstage her.

But as they continue, I relax, seeing that this is, perhaps, for the best. If they sing together, there will be absolutely no doubt in the audience's mind of which one is the better singer. Carlotta is no match for Christine, and apparently she begins to realize this truth, for her voice becomes rougher, more desperate, strained, while Christine soars, reaching heights I had not anticipated on this night.

Finally, Carlotta drops out altogether, leaving my angel to finish the aria on her own. The end comes with such quiet beauty that I almost weep, my hands clenched to my heart. Oh, Christine… Christine…

Then comes the applause – loud and long, just as I had known it would be. The company hails her tour de force with enthusiastic and appreciative applause, and I smile, there in the darkness. She has astounded them all, and now there will be no turning back. She has sung even better than I had expected, and soon all of Paris will be bowing at her feet. All is proceeding according to plan.

Steps abruptly crack across the cobblestones, and I bend my head, the wide, dark brim of my hat shading my face, or rather, I think caustically, the stark white of my mask. At least I should have worn my black mask tonight, but I had been in far too much of a hurry to think sensibly.

Ah, it is the doorman, that Jean-Claude. A good fellow, follows my instructions for the most part and is respectful of my presence. A bit simple, but loyal nonetheless. And he cared for Christine when she arrived, which shows his heart is very much in the right place. But who would not care for Christine? She is loveliness itself, a goddess among much lower beings, kind and thoughtful and innocently eager to please.

He pauses and looks around warily as I whirl around the corner, gloved hand touching my hat brim to hide my mask, and assume the position of so much baggage heaped in the short, grimy alleyway. I know he is suspicious, and I hold my breath, my body boneless beneath the shelter of my black cape.

Finally, his steps move away and up the staircase, and I reclaim my spot at the corner of the stairs. Perhaps I will wait for Christine here, surprise her as she comes out, and show her that her maestro came to hear her sing. For she should soon be on her way – she pledged to return immediately to the opera and tell me of her performance. Undoubtedly that young pup of a comte will try to detain her, but I have faith that Christine sees through his lovestruck façade and will do as she promised.

There is a movement at the upstairs window, however, that catches my attention. I peer up beneath the brim of my hat to see Gerard looking down, an indescribable expression on his face. I did not know he was here as well, but I can see something akin to disapproval in his eyes, and I have no desire to be lectured. Christine will have to find her own way back to the opera. I will wait for her there.

I move back into the alleyway, melting into the shadows, moving from dusky shades to even deeper gloom.

The very heart of darkness. Blackness itself.