This is a solid-state Tesla coil. The primary runs at its resonant frequency in the 41 KHz range, and is modulated from the control unit in order to generate the tones you hear. So just to explain a little further, yes, it is the actual high voltage sparks that are making the noise. Every cycle of the music is a burst of sparks at 41 KHz, triggered by digital circuitry at the end of a “long” piece of fiber optics.

                                      

This is a shot of a dell computer being smashed with a sledge hammer @ 532fps. This was filmed with a SVSi GigaView high-speed camera.

                                      

This is a shot of a woman running through a field of wheat. This was filmed at 532fps with a SVSi GigaView high-speed camera.

                                      

This is a high speed video of a boxer/lab mix shedding itself of some water.

                                      

This is jello being dropped at 1000fps. This was filmed with the SVSI, GigaView Camera.