You put the headphones on and the room falls out from under the sound. Fifty people bobbing, mouthing words, laughing at a chorus you can't hear, and around all of it, just the shuffle of sneakers on the floor and somebody's actual breathing. Three channels, three colors on the little switch.
Green, blue, red. You flip to red and the woman next to you is suddenly dancing to a completely different song than she was a second ago, and she doesn't know you know.
That's the part I keep looking at. Everybody in there is certain they're all in the same place. They're not. Each one is alone inside a private thing pumped straight into their skull, and the only proof anyone else exists is that they're moving too.
I spent six months breathing air I couldn't see and couldn't trust, sealed off from a hundred people I loved by a wall and about four hundred kilometers of nothing. You get used to being your own sealed room. What you don't get used to is that it never has to look like isolation. From up there you can't hear a single thing happening below you. The whole planet is dead silent and full of people dancing.
Then somebody grabs your wrist, points at their switch, mouths "blue," and you flip to blue, and for one song you are demonstrably hearing the exact same thing as another human being. You can watch them count you into it.
That's the whole trick, I think. Not the music.
The reaching over to sync somebody else's channel to yours, in a room where nobody would ever know if you didn't.