Bop Spotter isn't much to look at: it's a plastic box attached near the top of a light pole located in the heart of the Mission District — one of San Francisco's most densely populated and diverse neighborhoods.

But that box — which contains an old phone programmed to run the music identifier app Shazam — has been quietly capturing the area's cultural vibes for just over a week.

"Bop Spotter's like a living time capsule in real time of what songs are playing," said Bop Spotter's creator, Riley Walz.

The 22-year-old software engineer spends his spare time dreaming up oddball projects, such as a fake restaurant that mostly existed only on the Internet, and a random route generator for pedestrians and cyclists.

How it works

Walz said he spent about $100 and a couple of weekends working on Bop Spotter, which he installed using a friend's ladder in the middle of the day on Sept. 28.

"No one came up to me asking what I was doing," Walz said.

A solar panel on top of the box keeps the phone powered up. A microphone on the bottom captures songs it hears nearby and logs them on the Bop Spotter website. The system runs on the neighborhood's free public Wi-Fi network.

The system logs about 150 tracks a day by an array of artists including Nipsey Hussle, Celine Dion, The Temptations and Peso Pluma.

Defining the urban soundscape

"One of the things that really defines the urban soundscape to me is all the music that you hear coming out of car stereos, people's phones, from retail stores and coffee shops," said Nate Sloan, a University of Southern California musicologist and the co-host of the Switched on Pop podcast. 

Because these songs generally exist in the public space only for a few seconds — the car drives off; you walk past the coffee shop or store — Sloan said Bop Spotter can be a useful way to preserve their imprint on a particular landscape.

"This kind of captures those sounds and records them in a way that makes it this really wonderful archive of a specific intersection," he said.

Questions about surveillance as entertainment

Other scholars, such as Washington University in St. Louis assistant professor Sarah Koellner, who researches culture and surveillance, said Bop Spotter raises serious questions about contemporary surveillance culture.

"Do we enjoy the entertainment? Or is it something that we're actually appalled by, that someone is listening in?" Koellner said.

Walz said he named Bop Spotter after ShotSpotter, a surveillance technology police departments use to track the location of gunshots. But he’s not trying to make a political point.

"This is culture surveillance, where I'm picking up on people's activities down here," Walz said. "But it's just music." 

The project is resonating. People in places like New York, Boston and Berlin have gotten in touch about creating their own Bop Spotters.

Seattle artist and digital strategist Rachel Stoll said she heard about Bop Spotter from a friend in Iceland and now wants to recreate it in her city.

"It's like the fun part of surveillance capitalism," Stoll said. "We're all being monitored all the time — by our phones, by cameras. But this is a way to take that, flip it, and pull something that's fun out of it."

Walz said he's excited to get a network of Bop Spotters going around the world and compare the musical findings between cities.

He’s also been joking about creating a version of Bop Spotter that captures peoples’ sneezes — and then yells “bless you!” in response.

"I have a very long list of things I want to make," Walz said. "And every weekend, I like look at it and take one thing off."

Jennifer Vanasco edited the audio and digital pieces; Chloee Weiner mixed the audio version.

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