A Twilight Music Box
The study of magic in Equestria was constantly advancing, be it a new spell that shot forward the idea of what magic could accomplish or a deeper understanding of how magic worked. Things such as this were usually taken on by those who went to school for years. Ponies who then "mastered" their branch of magic and decided to dive even deeper into the world they knew, eager to find what makes it tick.
Twilight Sparkle, the pony who sat at the paper-filled writing desk in the study of a large crystal castle, was almost no different from those who studied among her, or so she liked to think. The lavender mare who sat at the desk thought herself to simply be a scholar among scholars when, in fact, she was the example that most scholars tried to live up to.
The alicorn mare who was deep in focus was not just an average scholar; she was the personal student of the solar goddess. She learned the magic of the moon priestess and flew with the dragons of old. Twilight walked the ancient caves digging with the sharp-clawed diamond dogs, ran with the green-plained Buffalo, danced with the Fire Phoenix, and dueled with death's blade wielded by wendigos so cold.
Twilight Sparkle was no ordinary scholar; while a regular pony would spend a lifetime mastering one magical art, she was determined to master them all in the time she was given. Thanks to her ascendance, that dream was now a reality. While the public knew Twilight by the title she was given at her crowning, The princess of friendship, to those who valued knowledge above all else, she held a much different title: The princess of magic.
They hailed her as a magic prodigy, a goddess of arcane Understanding. She brought them to a magical golden age; every subject of knowledge she touched changed, driven to new hights by a mind that seemed to hold the secrets of the world. The topics she studied were unlimited in scope; no project was too easy, no answer to lost to find. She found them one way or another; even the darkest corner couldn't hide an answer once the magic princess shone the light of her mind on the problem. Yet even she had limits, and even the gods could suffer from the accidents of the universe.
It would be the study of harmonious musical magic that would break the unbreakable. The magic of harmony was well known, as was the study of magical music, But the study of harmonious musical magic was a new field that had emerged of late. Equestria had been at peace for over a thousand years, and the latent harmony built up over the centuries. A by-product of such peace has started to affect the magic around them. The power of song and music was one such thing that baffled the magical community. It was with this that she was determined to unlock its answers.
She started with the musical aspect; why could music be felt by so many? Why could music reach out and touch the souls of those who listened, yet even with magic, the soul music couldn't be reached. It was a topic everypony knew, a fact of the arts, that the world's music could reach out and touch your very soul, yet you couldn't.
Magical music was different, especially when combined with the harmony that flowed through Equestria. In contrast, music could touch one individual soul, while it could affect each pony differently. Magical music powered by harmony could reach into a group of ponies or, in this case, souls and link that group together to one wave of thought for a short time. This was the running theory on why musical numbers with no planning or coordination could be done; with the power of magical music, every pony already knows their parts.
It was a shame then that even after years of grueling research and countless experiments that one couldn't get it to happen on purpose, it seemed to just happen freely, to go off when the harmony and magic of music seemed to be at a high in one area. Every test was met with this outcome; no amount of magical prodding or spell weaving made this happen on cue, that was until now.
Twilight had finally found the answer, harmonious Musical magic was a form of soul magic, an honest-to-goodness form of natural, neutral soul magic. Magic that was lost to all but a select few, and for a good reason. It was thought to be an evil form of dark magic that could be used to force those to be puppets of masters who, in truth, never had good intentions. Twilight had only been taught by priestess Luna recently and was still far from mastering the old art. After this discovery and many more restless nights of spell crafting and research, Twilight finally believed that she had a spell that could do the impossible.
It combined an old music box, one of Twilight's favorites. It held the tune of a slow, sad tone. One inspired by the casting of a long-lost spell, combining this music with the harmony around her, she could add in the magic to mix with the harmony to bring the spell to activation, yet even then, it would require one more activation key, a piece of a soul. Typically when a group of ponies was together, the activation of harmonious Magical music would be done just from the sheer volume of the souls around the activation area, so no pony would feel any adverse effects. It would require more sacrifice if one was alone on the other hoof.
So on a dark night with a storm raging outside her castle walls, Twilight set her spell into motion. She set about weaving arcane lines of magic as the music box played, the slow melody filling the air with its somber tune, Twilight's horn glowing with lavender light as she poured power into the spell. The magic build-up hadn't gone unnoticed by the storm raging outside, and with a stroke of misfortune, the energy from said spell drew the ire of the lighting that the clouds birthed.
Twilight was careful; she had to be, stitching each piece of the spell together with a calm mind; finally, it came to the most dangerous part. Priestess Luna had always warned her about using soul magic; the slightest mistake could, at even the best of times, lead to death. So Twilight moved carefully around the magic well of her soul, she planned only to take the tiniest sliver, but the world had different plans.
Twilight wasn't prepared for the lighting that shattered the crystal window to her side. She couldn't compensate for the surge of magic power that flared in her horn, and without even having time to understand what was happening, the body of Twilight sparkle fell limp.
It was to the grinding of gears that Twilight Sparkle would awake too, her mind slowly waking up from the fog that covered it. The world around her coming into view; her eyes had opened as soon as she had woken up. She moved, going to shake off the stiffness that came with deep sleep or at least tried.
She was in the room of her and Celestia, the one back in Canterlot; her mind racked itself thinking on how she had gone from her basement to their room, her mind grinding with the same slight grinding noise that a music box would make. She tried to perk her ears, doing her best to listen past the grinding sound that echoed around her, yet like the rest of her body would respond and refuse to move. Panic started to overtake her, and she tried with all her might to move around, yet her body remained still as a shaped statue.
The gears grinding soon faded away and left only the playing of a music box in Twilight's ears as her mind did its best to fight through the genuine panic; Twilight fought against her own unmoving body, trying to scream, willing her mouth to make noise or even move. Then she started to move, yet as the happiness of such a thing welled it, it died in its infancy as Twilight realized the movement was not under her own power.
Her body was spinning; the music playing in her soul forced her to turn slowly, showing off Celestia's room to the trapped Twilight; she watched as the room spun slowly around her. Yet, as it passed by, Twilight noticed something odd, it was much larger than she had ever realized. Of course, Celestia's room was big, but now it looked absolutely massive. Twilight drowned out the creepy music that played, still not seeing the source as she had a more important thing to worry about. A weeping Celestia.
Twilight instincts raged against the prison she was trapped in, trying to do anything as she watched her wife crying on their bed, yet it was no use as she slowly spun away from the scene, left with only the silent crying and sniffles of a weeping princess. The door to the room opened soon after a very distressed Luna made her way in; Twilight only got a glimpse of the black dress one would wear for a funeral.
Luna's sad, hollow voice would shake Twilight to her very core "it is time, my sister; the funeral will take place in less than an hour."
She passed by the sister, watching intently as Celestia made ready, the black dress of death sitting upon her form like a cloak of mourning; her tear-stained face and red puffy eyes spoke to how long the mare had been crying for. Twilight spun away again, her mind almost paralyzed at the sight before her. The music played in her ears as she turned.
She passed by them again, spying on Celestia with the veil of a window in mourning, her face covered in the black of death and grievance, for a point that shone so much light into Twilight's heart that only left one question, who had died? Twilight watched as Luna used her magic to open a golden box revealing Twilight and Celestia's wedding rings; with the blue magic, she reached around Celestia's ring. It was a golden ring that spiraled up the horn, ending in a star that was Twilight's cutie mark.
Twilight watched as the ring slid down Celestia's horn stopping at the base of her head. Luna gave her sister a hug as cries racked Celestia's body. She watched Luna comfort her sister as they embraced each other, each holding the other up as grief took hold. With the last sniffle, they separated, Luna keeping a wing over a broken Celestia.
The world started to slow, much to the already scared Twilight's horror. The once loud music in Twilight's head skipped slightly, the world around her going dark as the music ended, her typically sharp mind coming to a slow crawl as she tried to fight off the growing need to sleep. She couldn't stop now; something was wrong with her, Celestia, and everything.
Next, with a sudden hold of the music box gears, the spinning room that Twilight knew stopped, leaving her staring blankly at a small mirror across the room. It was there that she saw what she was. It was her, yet it wasn't. A figure of her stood upon a music box of golden crystals and gems. Her form danced happily to the music that played, a smile etched into her unchanging face even with the death-induced panic flowing through her. Then with a sudden jolt and the end of the music, the waking world faded to permanent black; with no time to think, fight or cry, Twilight was no more as she fell into the timeless void of unconsciousness.