Disclaimer, et al: Don't own them, sadly. Oh my god, if I knew I'd tell you. I know what my intentions were, and they were all honourable. As it happens, things never go the quite the way I plan. I shouldn't even be allowed to call this Zemyx, but in my mind the whole thing is totally obvious. (Dear god, I shouldn't even call it a thing.) Anyway, have at it!
The Science of Song
1.
It doesn't happen once, twice or even three times. He knows that bad luck comes in threes. When it happens for a fourth time he starts to think the situation is ridiculous.
2.
The first time it happens he's sitting in the kitchen, and a row of knives are laid out in order of size on the counter in front of him. He doesn't know who laid them out like that (although his first thought is Larxene) but they look so clean and sharp, and he starts to wonder what sound they make. He lifts the smallest and chinks it against a glass, then scrapes it along the edge. The sound is abrasive, so he resumes tapping it against the edge until he finds a beat he likes, multiplies it with another knife, and continues for several minutes, until a man walks through the door and glances at him on his way to the fridge. The beat stops.
3.
The second time he is sitting in his own room with his sitar on his lap, strumming without a specific tune in mind. He thinks empty chord, and almost drops the instrument when someone (the same someone as before, he discovers) enters and informs him that the Superior wants to see him.
4.
The third time--the one he believes to be the last time, according to the rules of bad luck--is during the night. He finds it hard to sleep when it's raining outside, because the sound of it distracts him; it's the sound of fighting, and he can't sleep when he thinks about fighting because it reminds him that he has to improve or he really will be nobody, the black sheep of a group of outcasts. He wanders out of his room, and the corridors are so bright that he almost forgets it's the middle of the night. He starts to sing. He's tired, so the words are slurred, but he continues until, without any warning, the man passes him. Demyx has no idea where the he's been or where he's going, and the note on his tongue falters. The man passes without any comment about how loud Demyx is being, how late it is, or why the hell he's wandering around singing in the first place.
5.
Today, Demyx is sitting in the kitchen again, and the man is sitting in the same room. He doesn't seem to be sitting with Demyx, and his eyes are focussed on the sheaf of paper in front of him, so Demyx decides that it's safe. He plays a few notes and it doesn't garner any reaction, so he plays the song in earnest, and there are no interruptions.
He sets the sitar down beside him, and only then does the man look up. He looks at Demyx for a few seconds. He says, "It's ingenious."
And Demyx chalks up the fourth time, because he has no response.
Zexion raises an eyebrow and looks at the sitar before turning back to his notes. "Sound travels faster through water."
6.
He looks at his instrument and is silent. The situation is ridiculous, but for a moment he believes he is not.