
New York City is notoriously loud. Cabs honking everywhere, thousands of people flocking to the streets at all hours, and cars blasting music for all to hear.
But while some of us hear only noise, others hear music. Joshua Wolk is one of those people. The designer is the creative mind behind Train Jazz, which turns the rhythm of NYC’s subway into an interactive musical website.
Train Jazz started when Wolk came across New York City’s open repository of transit data. He first created a soundless live map of the city’s transit.
“It felt unfinished. I soon realized that music was that missing piece,” he tells Fast Company.
Wolk ended up assigning an instrument to every train line across the various boroughs. On the website, users see a simplified map of the Metropolitan Transportation Authority (MTA) subway lines, showing the active trains running in real time. Every note is played based on where a train is along its route, coming together as a sonic tapestry of the city’s movement.
When playing around with the website, users can hover over a panel displaying the symbols for each line. The number of trains running for that specific line then appear, alongside more information regarding the line’s history and the instrument it’s been assigned.
A sound for every train line
The specific sounds and instrument associated with each line are influenced by Wolk’s research on each line. For instance, at the time of publishing, the F line had 51 trains running in the city. “The F is famously unreliable—its sound wobbles like a player who can’t hold a pitch.”
Or take the Z train, which plays soft maracas only during rush hour, when the train runs. The Z’s sound has half the strength of its other brown line counterpart, the J, which routinely runs throughout the entire day.
“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,” the site reads. “Whatever is playing now has not played before and will not play again.”
The map is updated every 15 seconds, with the website fetching every train’s coordinates from MTA’s API, Wolk explains. The project also reacts to location, with trains near the user growing louder than the rest.
“You are listening to a portrait of where you stand, played by the city you are standing in,” the site adds.
Though the sounds can be discordant depending on which trains are running, it’s free-form and beautiful in the way that only jazz is. “My rule was that Train Jazz wasn’t complete until it was something I could listen to for three hours straight,” he says. “That required putting a lot of care into how the notes float through the chord progressions.”
Ultimately, Wolk wants to take his virtual project to the real world.
“The internet is cool, but my dream is to give Train Jazz a physical home in New York: A wall, a bus stop, maybe even the MTA,” he says.



