I’ve just found an article from defunct Canadian digital art and culture magazine HorizonZero that traces the history of electronic music generated from human EEG recordings.
In the late 1960s, Richard Teitelbaum was a member of the innovative Rome-based live electronic music group Musica Elettronica Viva (MEV). In performances of Spacecraft (1967) he used various biological signals including brain (EEG) and cardiac (EKG) signals as control sources for electronic synthesizers. Over the next few years, Teitelbaum continued to use EEG and other biological signals in his compositions and experiments as triggers for nascent Moog electronic synthesizers.
Link to ‘A Young Person’s Guide to Brainwave Music’.