The rapport radio is the ultimate mood music – a radio that changes tune to suit how you are feeling.
British students have invented a camera and face-recognition software that detects a listener’s
mood and picks a suitable song.

If they are happy with the choice and smile, the radio increases the volume; but if they frown, it tries another tune. A very angry look tells it to switch off. http://mzfacts..com/2014/07/radio-tuned-to-your-moods.html