A Tesla Coil is a transformer that is able to generating extremely large voltages, which allows it to throw huge but extremely short-live sparks. So what looks like one long spark is actually a bunch of sparks each second. As any musician with a scientific background will tell you, a given tone is a given frequency of vibration, producing each unique note. So by adjusting the sparks per second from the coil, different notes can be played. And that is exactly what they did in this video; enjoy!
The coil was invented by Nikola Tesla, who also invented AC power, the electric motor, the alternator, the generator, the audio speaker, radio (they took the patent away from Marconi when it turned out it was based on 17 of Tesla’s patents), the florescent light four years before Edison used brute force slave labor to invent the light bulb, and ever so much more which he patented. He also invented some stuff the patent office couldn’t figure out how to process, like broadcast energy and the related wireless charging of batteries (a company finally figured out how to make a profit on that one a decade or so ago for all our portable electronics), Ball Lightning, Radar (it was WWII before anyone decided building that could be useful), and oh, yeah, that earthquake machine he almost sank Long Island with. Tesla has been one of my personal heroes since I was a kid, and if you don’t know about him it is time you learned.