Ferrofluids are liquids that become super magnetised when they're in contact with a magnetic field. Ferrocious is a ferrofluid sculpture that uses the hyper-magnetic material respond to sound, like a high-tech musical lava lamp.
Noises like your voice or the beat of a song will cause the copper coloured electromagnet at the top of the piece of art to trigger the inky black ferrofluid, which will respond to low-frequency noises -- typically 250Hz and quieter -- like vocals, percussion, bass, bassons, and guitars. It bounces around differently to various sounds when you set it near a speaker or plug it into your headphone. And the circuit board and magnet are both exposed, for a little extra flair.
Ferrocious is just a Kickstarter at the moment, and given Kickstarter's less than perfect track record for followthrough, at this point we're really just considering it a prototype. A beautiful, dancing prototype that looks better than any lava lamp you've ever seen.