In a fourth-floor Tufts lab, a computer program was in the process of convincing a student that she was actually interacting with a human. It was spring 2015, and the student had come to the lab for a study involving a new way of teaching people to play the piano. The beginning of the session had been fairly unremarkable. The researchers--Beste Yuksel, E16, then a Ph.D. candidate in computer science, and Kurt Oleson, A15, a brain science major with a minor in music engineering--put a headband-like contraption on the student's head and sat her down at a piano keyboard. In front of the keyboard was a computer screen that displayed the soprano line of a Bach piano chorale that she was supposed to play.