A study at the University of London found that listening to happy or sad music made a happy or sad face look happier, or sadder to a person, but not so much as to lead to a misinterpretation. When looking at neutral faces, listening to happy to or sad music gave the person a perception bias which caused them more likely to interpret the face as expressing an emotion similar to the music playing.
In the Kids Cooperate social skills groups we work on becoming better interpreters of the faces of the people we are speaking to as a way of gaining introspection into their thoughts and emotions. Music is a powerful tool to enhance the ability to understand the emotions expressed in subtle facial variations. In group we always have a variety of music playing that implies a range of emotion to provide an ambient boost the the ability to read emotion.
Here are a few standards on the playlist:
The Be Good Tanyas
The London Symphony Orchestra Plays Star Wars