OK. What we have here is a video about a new candle-powered guitar effect. It is, in fact, the world's first candle-powered guitar effect, which probably doesn't come as too much of a surprise.
Z VEX Effects' Candela Vibrophase produces a mono output, creating a "3D" rotary-speaker effect that's combined with phasing, wah, vibrato and tremolo.
The effect's hypnotic sound is produced using no batteries or power supply—just a candle in a tea light, which drives two solar cells and a Stirling heat engine that spins an optical control disc whose design can be controlled by the user.
If all this sounds confusing, just watch the two videos below (especially the top one). The top clip is the official Candela Vibrophas demo; the bottom clip was shot by a 2016 Winter NAMM Show attendee, but it shows everything up close in the bright lights of the lovely and talented Anaheim Convention Center.
It turns out I could've seen a demo at the NAMM Show last month, but I totally missed it.
For more about Z Vex Effects, visit zvex.com.