She said other studies examining the impact of music suggested there might be some types of music which were less good for the heart - with heavy metal more likely to raise stress levels, while opera, classical and other types of 'joyful' music were more likely to stimulate endorphins.
dddddProf Ilic said: "It is also possible that it is better to have music without words, because it is possible that the words themselves can upset the emotions."