Quite honestly one of the coolest things I’ve ever seen. I did not know that this actually worked, and by ‘this’ I mean that Tesla coils can produce sound. The sounds you are hearing is actually being produced by the electrical sparks themselves, and apparently it is incredibly loud, (over 110 dB’s). Enjoy! (I have also included the notes from the video, as I thought they were quite interesting.

Twin Solid State Musical Tesla coils playing Mario Bros theme song at the 2007 Lightning on the Lawn Teslathon sponsored by DC Cox (Resonance Research Corp) in Baraboo WI.
The music that you hear is coming from the sparks that these two identical high power solid state Tesla coils are generating. There are no speakers involved. The Tesla coils stand 7 feet tall and are each capable of putting out over 12 foot of spark. They are spaced about 18 feet apart. The coils are controlled over a fiber optic link by a single laptop computer. Each coil is assigned to a midi channel which it responds to by playing notes that are programed into the computer software. These coils were constructed by Steve Ward and Jeff Larson. Video was captured by Terry Blake. What is not obvious is how loud the coils are. They are well over 110dB If you look at another You Tube video which is from a different angle, you can hear the echo off the building and get a better idea of how loud it is.