The present study investigated affective and physiological responses to changes of tempo and mode in classical music and their effects on heat pain perception. Thirty-eight healthy non-musicians (17 female) listened to sequences of 24 music stimuli which were variations of 4 pieces of classical music. Tempo (46, 60, and 95 beats/min) and mode (major and minor) were manipulated digitally, all other musical elements were held constant. Participants rated valence, arousal, happiness and sadness of the musical stimuli as well as the intensity and the unpleasantness of heat pain stimuli which were applied during music listening. Heart rate, respiratory rate and end-tidal PCO(2) were recorded. Pain ratings were highest for the fastest tempo. Also, participants' arousal ratings, their respiratory rate and heart rate were accelerated by the fastest tempo. The modulation of pain perception by the tempo of music seems to be mediated by the listener's arousal.