626 · empty room
An empty room, in the dark, with company you can only hear.
Close your eyes. Several unseen presences drift around you in 3D space, each a soft, sustained voice. Turn to face one and it opens up and sings; the others recede. There is almost nothing to see — the payoff is in your headphones.
Headphones strongly recommended. On a phone, hold it up and turn your body.