Dubstep Through Magical Handwaving

In December 2014, I build this prototype for an unusual musical instrument. It was extremely hacky and the source code and hardware schematics would make your eyes bleed, so just let me share the most important part of it:

My first live concert!

I call the song "Snorting Sawdust". It was 100% improvised. :'D

Admittedly, there's no actual magic at work here. The mechanism is explained in the following diagram:

diagram

With an Arduino, I measured the capacitance between the frame of my laptop and the frame of my metal chair, which was connected to the Arduino through a long wire with a magnet soldered at the end. The person sitting on the chair acted as the dielectric material between the laptop and the chair, whose dielectric permittivity ε was constantly measured by charging and discharging the capacitor (i.e. laptop frame and chair). The time to charge was then used to select dubstep samples to play. :)