Sherlock was watching from his usual Box 5 and plugging his ears. He had built this Opera House for music, not for some loudmouth with horrible vibrato called Piangi to steal the stage on every show. Today, he came in excitement though, because he had rigged one of the backdrops to land on him during dress rehearsal. He wanted to know what the other people in the company sounded like, and with Piangi's deafening voice, he could hear nay one of them. He watched in amusement as it fell on him, smiling the smallest bit as the man stormed out of the theater in anger.
He saw Monsieur Moriarty talking with the idiot managers of the Opera, noticing a blond man, one of the elephant tamer dancers, stepping up to sing.
*This ought to be interesting* He thought as the man began to sing. It was amazing. He had never heard a voice so pure. It was not perfect, but he was like a blank slate with not bad marks on him.
He scanned him up and down.
It was John Watson. He was a dancer that he'd seen before, never paid him much mind. He was the son of a Swedish Cellist, Vincent Watson.
He made his decision to see him again, finding him after his great performance the next evening. He was alone, praying for his dead father. Sherlock looked up through the vent and sang, using his ventriloquism to make it sound to John as though the voice was all around him. "Bravo, bravo, bravissimo!" He sang happily before he saw John's friend, Molly Hooper walk into the room to congratulate her friend.
Okay, so his plan had failed. So he would talk to him some other time.
He decided to talk to the managers -using Monsieur Moriarty as a go-between- and sent them a letter that read: 'Greetings new managers Anderson and Donovan. I welcome you to my Opera house and wish to remind you that my salary is due. You will obey my commands and leave box 5 empty for my use during every show, or I will terrify your guests away. Sincerely, O.G.'
He then used his tunnels to travel immediately to John's dressing room, looking at him through a trick mirror. He flipped a switch and turned off the lights of the room, quite terrifying John in the process.
"Wh-what the hell is going on?"
"Do not be afraid. I have come to teach you." Sherlock replied loudly and clearly, once again using ventriloquism to prevent John from finding where he was.
John's stomach dropping when he heard those words. "Who are you?!"
"Vincent, your father, told me to watch over you. I am your Angel of music." the voice replied.
John looked around, still wondering is he was being tricked. "Where are you?"
"I am with you. I have always been with you, but you could never hear me until your resolve and love for music was strong enough."
"Show me your face. Do not hide from me. If you truly mean what you say then are no foe."
"I can show you, but Angels do not look pleasant to the human eye, you may not want to see me. Are you quite sure?"
"If you are my angel then I need not care what you look like."
Sherlock opened the trick mirror, allowing John to see him. He was dripping with fog, and half of his face was covered, but he looked human.
He reached out his hand to John. "Come. I will teach you."