Fermilab Technician, U of I Student Make Tesla Coils Sing

Tesla coils attract attention. The arcane, high-voltage technology that drives them powered the very first particle accelerator in 1928 and today, it is used in television picture tubes and in the backyards of amateur enthusiasts. So it was no surprise to find a Tesla coil at the DucKon science fiction convention in Naperville last June. A crowd gathered ready to hear the typical crackle and watch the purple sparks.

But the coil began to take on a life of its own. Its pitch and frequency fluctuated, and as the sound started and stopped, musical notes began to emerge. Someone in the crowd held up a lighter while another listener shouted out a musical request for the Lynyrd Skynyrd song "Free bird."

Thanks to that premier performance and videos on YouTube, the singing Tesla coils' creators Steve Ward, a student at University of Illinois-Urbana, and Jeff Larson, a senior technician at Fermilab, have become the rock stars of the Tesla coil universe. Their first YouTube video has received almost a million hits.

Larson estimates that a few dozen Tesla coils make music, and most of those are small. "Our set up got so much attention because it was so big," he said. "Most musical Tesla coils are only a few feet high and shoot sparks that are a couple of feet long. We can produce 12 feet of spark with ours."

After Ward mastered the original Tesla coil, Larson built a twin. "They can play in chorus or as a duet," said Ward, who has written music for the Tesla coils to play.

Together, the musical Tesla coils can play everything from the theme to the Mario Brothers video game to the "Dance of the Sugar Plum Fairy."

The music is created when a laptop computer signals the coil to produce a spark, which heats the air making a popping noise. Sparks emitted in rapid succession create a buzz and eventually a musical note. Ward and Larson control the frequency of the sparks to create whole songs. The music is so loud that some audience members can't believe that it is the Tesla coils' sparks that are responsible for the song they are grooving to.

"People came up to me asking, 'Where are the speakers?' and there aren't any," Larson said.

— Haley Bridger