By using the Star Wars Force Trainer toy, these guys hacked it along with Arduino to control sound. I think this is actually a great way to make a brain-controlled device of all sorts.
Hacked EEG wireless headset produces a pure musical tone when a user concentrates. When not concentrating the user heres a combination of voices – one must find the right tone in their mind among chaos . Connected to Ardunio Nano, and running PD on a connected laptop to generate music. Toy parts for less than $150.
The brain-controlled music device:
The original Star Wars Force Trainer Toy: