Screengrab via The 101 Plays Itself Have you ever played Guitar Hero or Dance Dance Revolution? They’re fun video games that use a never-ending scroll with multiple “lanes” that, when struck at the right time, play different notes—whether you hit those with your fingers on a toy guitar or your feet on a floor pad depends on the game. What you’re looking at here is the same concept, but with a major highway as the scroll and real-life cars as the instruments. Does that make any sense? The creative mind behind “The 101 Plays Itself” is music producer Jay Judah, and his website uses public-access Caltrans traffic cameras on U.S. Highway 101 in Los Angeles, or, as locals call it, “the 101,” to create music. Here’s how it works: when cars drive through a predetermined line that Judah’s software superimposed on the video feed, they play a note. Since this portion of the 101 boasts five lanes, the system can play up to five different notes simultaneously. I’ve been watching this for about 20 minutes now, and frankly, it’s really cool and extremely creative. A heads-up: the page has been spotty throughout the last day or so, so there’s a chance that when you load The 101 Plays Itself you might get a note that says “Cameras Down.” Because the application relies on the Caltrans feed, it sometimes drops for a few minutes but then comes back up. Just circle back later, and chances are it’ll be working fine. The 101 Plays Itself At the time of writing, I could choose from two cameras: 101 Southbound at Moorpark St. in Studio City, and 101 Northbound at SR170 Tujunga in North Hollywood. The more cars drive by the line, the more notes are played, and the longer you can dance to the music. But wait, there’s more! Scroll below the video feed, and you’ll notice a sound pad of sorts, which allows you to choose which types of sounds you want to hear when the cars cross the line. You’ve got choir, organ, strings, marimba, and my favorite, drum kit. You can even choose several sound types at once in order to try to emulate a little groove. Below the sound pad, there’s a counter that’ll tell you how many notes have been played since you loaded the page (which also means how many cars the system registered crossing the line), the passing speed, and other metrics that I can’t imagine are useful for much, but they sure are fun. In Judah’s own words: This page is playing a public Caltrans traffic camera live. Nothing is pre-recorded — the timestamp burned into the top of the picture is the real one, and if you come back at three in the morning you will hear an almost empty freeway. Ten sampling patches are laid onto the road surface, two in each of the five lanes. They are not rectangles: each one is a slice of its own lane, leaning and narrowing with distance exactly as the lane does. Your browser reads those patches fifteen times a second and watches for the road to stop looking like the road. That is a car, and that is a note. Underneath, the timing comes from ten small sampling patches on the tarmac, two per lane, each a slice of its own lane rather than a rectangle. A vehicle trips one and then the other, and the gap between them gives its speed — a real speed trap, 13.4 metres long. How long it covers a patch gives its length, which is how the page tells a truck from a car and hands it a different voice. The 101 Plays Itself This reminds me of that musical road in Lancaster, California, that was featured in an episode of Top Gear back in the day. Drive it at exactly 65 mph, and the sound from the tires plays the famous William Tell Overture because of the grooves carved into the tarmac. The 101 Southbound at Moorpark Street: where infrastructure meets music and tech.