Electrical engineering maestro Steve Ward, then a college student in Illinois, programmed this Tesla coil in 2007 so that each spark sounds like a musical note. In this now classic video, Ward shows off a stunning demonstration, which launched a new instrument now called the "zeusaphone" or the "singing Tesla coil."
Whatever it's called, it created quite a sensation. Singing Tesla coils were featured in the 2010 Disney film The Sorcerer's Apprentice and in a 2011 live performance by Björk.
The video explains some of the science behind it:
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.
Image credit: Malfet/Flickr