Musicians use their brain waves to play computer-generated notes while led by an 'emotional conductor' in Prague.

The graphs of those brain waves are projected onto one of two large screens above the orchestra. The performers launch sounds or affect their frequencies using EEG systems that measure their brain activity.

Two of the performers were given a task to watch a screen in front of them, with flashing rows and columns of letters, and told to look for a particular letter.

When they see it, 300 thousandths of a second later a signal appears in the EEG, causing a note to play.