Squid have chromatophores, or color changing cells, on their skin. The cells can adjust their pigmentation to dramatically and rapidly absorb or reflect light.
With this in mind, scientists took a suction electrode and attached it to the fin nerve of a longfin inshore squid. They then took an iPod Nano and played music into the electrode, stimulating the squid's nerve. For obvious reasons, they chose "Insane in the Membrane" by Cypress Hill. The testament should go to the musical taste of the squid.
The video is shown at 8x magnification so we can experience the rapid contraction and expansion of the chromatophores. via Backyard Brains