On YouTube, there’s a video of animated green mushrooms spinning around in a three-dimensional field, with a sound track of strange electronic tones. That premise itself is nothing extraordinary—the Internet is full of stranger things than dancing mushrooms. But what makes this video special is that the sounds are creating the images onscreen. Since the video first appeared last year, a lot of people have been skeptical about the 3-D graphics effect produced—including the editors here at IEEE Spectrum, until we dug out an oscilloscope and played the sound file into it for ourselves.
It’s all possible thanks to an old-school cathode-ray oscilloscope and a concept that many engineers and physicists will remember from their undergraduate days: Lissajous figures.
The mastermind behind the video is Christian Ludwig, an Austria-based electronic-music artist who performs as Jerobeam Fenderson and runs a small music label called Ordia Muszc. Through his oscilloscope musical projects, Ludwig creates audiovisual experiences, both online and for live audiences around the world. Ludwig says he used to make “a lot of rock music and other kinds, based on my favorite bands.” But more recently he’s been more interested in “experimental music and noise music, so I’ve tried to find some approaches to create something new that isn’t just sound,” he says.
As a teenager about 10 years ago, Ludwig took time off from school and did a vocational apprenticeship at Heidenhain, an electronics company. “It was not exactly the most creative job, but I did gain some useful practical skills there,” he says. “That’s how I got to know about oscilloscopes and electronics. I always thought I should do something with it because it somehow looks very cool. I like the laboratory aesthetics [that are involved].” After four years, Ludwig finished his schooling and started studying for a bachelor’s degree in sound engineering. Although he never finished his degree, he has taken that knowledge with him toward his endeavors in electronic music, in particular the oscilloscope projects that began two years ago.
Ludwig uses an analog CRT oscilloscope—specifically a Tektronix D11 5103N. When connected to a computer’s audio interface (in the case of the mushroom video, he used a USB-based RME Fireface UC operating with a 192-kilohertz sampling rate), the left audio channel triggers a horizontal deflection onscreen, and the right audio channel triggers the vertical deflection. “It’s like vector graphics,” he says. “Together, they can create certain shapes.”
In other oscilloscope works, Ludwig has created patterns and shapes of all kinds, including a magenta outline of a girl’s face in a piece titled “Khrang.” Typically though, the visuals are something much simpler and act to complement his music, whether it’s posted online or played during his live shows. Ludwig has just come back from a tour he did in the United Kingdom, where he thinks his performances were well received. With suitable hardware and the right kind of software for making waveforms (Ludwig suggests the Pure Data open-source visual programming language or the commercial visual language Max), anyone can emulate his work and design their own sound-based visualizations.
Still, Ludwig sees this as a temporary interest. “I really want to do an album with this and more shows. But I think after a year or so I will go on with something else.” In the meantime, the interest his work has generated is likely inspiring other sound geeks to experiment with oscilloscopes in their own way. We may see more than just dancing mushrooms in the near future.
This article originally appeared in print as “Symphony for Oscilloscope.”