Intracranial electroencephalography was recorded in an epileptic patient when he was listening to dissonant and consonant chords and to minor and major chords. Changes in dissonance induced event-related potentials (ERPs) in the auditory areas from 200 ms onward, in the orbito-frontal cortex (500-1000 ms), and later in the amygdala and anterior cingulate gyrus (1200-1400 ms), suggesting the sequential involvement of these brain structures in implicit emotional judgment of musical dissonance. Changes in musical mode induced ERPs only in the orbito-frontal cortex (500-1000 ms), emphasizing the implication of this frontal region in emotional judgment of pleasant music.