Now, in the 19th century they had not yet invented the phrase "... and if you can't tell I'm being sarcastic," so when musical genius John Cage got a hold of this, he arranged the first public performance of the piece (840 times) in 1963 [though I will concede the genius of issuing timecards to the audience, who were refunded portions of the ticket price based on how long they remained in the audience.]
Though Cage arranged the performance in shifts with several pianists, the current experiment used but a single pianist, Armin Fuchs, who seems to be a "Vexations" specialist. So, for 28 hours, they recorded music and brainwaves. The researchers' site provides additional data, including MIDI files, EEG data, and a 660 MB mp3 file.
As for the results, to quote the Guardian article:
Fuchs's playing grew inconsistent during the periods of drowsiness. But when alert, the man was a model of consistency. "Most importantly," says the study, "whilst in deep trance, which included effects such as time-shortening, altered perception and characteristic changes in the EEG, the pianist managed not only to keep on playing but also to maintain a constant tempo, hence executing complex motor schemes at a high level of performance."
This is one of those experiments that is simultaneously stupid and interesting.