Eye- and face-tracking systems already help you communicate when your hands aren't an option, but what if you want to have some fun? You're covered there, too. Andreas Refsgaard has built Eye Conductor, an app designed to help the paralyzed (and virtually anyone else) make music. All you need is a computer, an off-the-shelf eye tracker and a willingness to look slightly goofy as you twitch your eyes and open your mouth. Unlike some previous attempts, it's all about having an accessible, flexible interface -- you know exactly what sounds you'll make, whether it's an experimental piece or a slick dance track.
This is a research project that's still in development, so you can't use it right away. However, it's not just a theoretical exercise. Refsgaard is hoping to release a web version of Eye Conductor sometime in 2016, and he wants to support alternative trackers like head-mounted mice. If all goes well, it could do a lot to enable creativity among those who normally have to sit on the sidelines.