Here is a cool device that lets you combine music and light to put on great shows. ViVi is an app-enabled music LED controller that lets you synchronize your light shows to music. It has a portable, wearable design. ViVi offers automatic volume tracking and a 5-volt power input. You can interact with it from an app.
ViVi does not require any soldering. It supports non-proprietary lights. Yet another interesting Kickstarter project.