Wesleyan University Scientists used electroencephalography to examine the differences in the brain activity of classical and jazz musicians during unexpected chord progressions. The study, published in the journal, Brain and Cognition, included 12 jazz musicians (with improvisation training), 12 classical musicians (without improvisation training), and 12 non-musicians, observing them while they listened to a series of chord progressions. Some progressions were typical of western music and others were unexpected progressions. Jazz musicians had a different response to the unexpected progressions that demonstrated increased perceptual sensitivity to unexpected stimuli along with an increased engagement with unexpected events.