(okay that's just my opinion)
seriously, it takes advantage of a physical principle of electromagnetism.
The part about moving currents create magnetic fields and moving magnets creating electric field, remember now from you last physics class??
When you supply power to this device, in the form of an amplified audio signal, the magnet dances, bumps, flips, and all out goes NUTS! in this little tube.
It is crazy to watch this, and all of the patterns that form while running.
really i tried to keep this simple, only using part i knew just about any average Joe could find around the house. Don't stick to my materials EXACTLY, expand use what ever you have!
-old pill bottle
-bits of wire
-hot glue (greatest stuff EVER!)
-coils or inductors from some TV's or speakers
-tiny pictures :P
-2 old CD's
-solder for the electrical connections.