“Two Trains” is a song by artist Brian Foo, the “Data-Driven DJ,” that charts the path of the “2” subway line in New York City as it travels through different neighborhoods in the boroughs of Brooklyn, Manhattan and the Bronx, using median household income as the driver for the dynamics of the instruments.
Between 3 and 30 instruments are playing during each segment of this song. Some instruments play softly (i.e. piano/pianissimo) and some play loudly (i.e. forte/fortissimo.) The number and type of instruments are selected based on that station’s surrounding median income taken from the 2011 US Census Data Release. In general, the higher the income, the greater the dynamics and quantity of instruments.