From dailygamesnews.com via YouTube

From Good Math, Bad Math.

Ladies and gentlemen.. For your pleasure and edification, allow me to present… The singing Tesla coils!

Yes, if you’re clever, and you’re willing to do a whole lot of work, you can operate a Tesla coil so that the sparking from the coil produces a particular pitch. Even you’re even more clever, you can vary the way that the coil is run to produce different pitches, and arrange it into a song. And if you’re really remarkably clever, you can set up two singing Tesla coils, and have them play a duet.