Conductor is a new project by Google engineer Alexander Chen that turns the iconic New York subway diagram (drawn by Massimo Vignelli in 1972) into a musical instrument. Using the actual New York City metro schedule, the music in the video occurs when various subway lines meet at a station; when lines cross they pluck a "chord."
By going to the website, you can pluck "strings" yourself or just watch (and listen) for what happens when the F train departs at 2:43pm. Changes have been made to the subway system since Vignelli's drawing in 1972, which are accounted for by only including no-longer-running "ghost trains" between the hours of 12-2am. Check out the video below.