Cheap ($2.50) LED driver that controls RGB stripe according to music bass line. Connected to 12V it detects music rhythm and flashed LEDs to the music.
This creates disco/club-like effect, visualizing BPM of your music.
Few modes: fade, flash, strobe. On the label it says that it can handle 3x2A output.

AliExpress link: http://s.click.aliexpress.com/e/4viHtDO