Audio Anesthetic

In one sweet but startling study on pain and music, participants “were subjected to increasingly painful shocks on their hands as they listened to music. … [And] as the subjects became focused on the melodies, they experienced more and more relief from the pain.” Another study in which children who listened to certain music after surgery and subsequently asked for less morphine seems to back this up, although a meta-analysis says the effect is possibly uselessly small. But what did they listen to?