This is how true Jedis make music.
You have to be a little nerd to have Star Wars toy that makes a ball levitate using your brainwaves.
But you have to be supernerd to hack this toy and plug it into a synthesizer and use it to produce sounds.
Check the result here, it is pretty cool.
In the words of the maker:
This is a brainwave controlled synth i made for a mate for his birthday. The frequency of brainwaves is sent from the sensor digitally to the base station, all I have done is mod the monotron to have a cv/gate input and added a few components to the force trainer to output a voltage determined by the brain activity sensed.
I found this here.