According to some researchers, music may help alleviate stress, by lowering the body's cortisol levels - the hormone released in response to stress. One mechanism by which music may alleviate stress is the effect it has on brainstem-mediated measures, such as pulse. heart rate, blood pressure and body temperature.
The effect is dependent on the type of music listened to:
"Stimulating music produces increases in cardiovascular measures, whereas relaxing music produces decreases," they explain. "[...] These effects are largely mediated by tempo: slow music and musical pauses are associated with a decrease in heart rate, respiration and blood pressure, and faster music related with increases in these parameters."
Music's effect on heart rate and its potential as a stress reliever has led a number of researchers to believe music may also be effective for treating heart conditions.
(Medical News Today, UK)