Every dot is a real subway train. Eight hundred of them, give or take, form a small jazz combo (walking bass, piano, sax, vibes, brushes) that has been playing without pause for over a hundred years. On the platforms they are hot, screaming, full of complaint. This is the music inside the noise.

The harmony moves through a slow chorus. A note is placed precisely where the train happens to be along its route. Rush hour fills the band with held tones; at 3 a.m. the silences grow longer. Whatever is playing now has not played before and will not play again.

Share your location and the trains nearest you grow louder. The piece rearranges itself around your body. You are listening to a portrait of where you stand, played by the city you are standing in.