This animation shows the flow of subway cars through New York City over one weekday.

Built with Python and Processing. Data from MTA and Google Maps API.

The background music is Rhapsody in Blue by George Gershwin. Gershwin conceptualized the piece while traveling by train to Boston. He told his biographer in 1931:

“It was on the train, with its steely rhythms, its rattle-ty bang, that is so often so stimulating to a composer – I frequently hear music in the very heart of the noise…. And there I suddenly heard, and even saw on paper – the complete construction of the Rhapsody, from beginning to end. No new themes came to me, but I worked on the thematic material already in my mind and tried to conceive the composition as a whole. I heard it as a sort of musical kaleidoscope of America, of our vast melting pot, of our unduplicated national pep, of our metropolitan madness. By the time I reached Boston I had a definite plot of the piece, as distinguished from its actual substance.”