As always science fiction edges towards science fact. The Royal National Hospital for Neurodisability is a world leader in treating patients with severe brain injuries. It has teamed up with Plymouth University who are developing a brain-computer musical interface (BCMI) and the result is the Paramusical Ensemble, a group of musicians who cannot play instruments by conventional means but who do so by sending signals from their brains to a computer, via electrodes placed on the scalp. This is the BBC’s report, including a video of a performance.
It is also worth looking at the RHN’s own press release on this ground-breaking piece of work.