From the New York Times
“Why We Like Sad Music”
The emotional experience of listening to music is an excellent way to separate thoughts from feelings and emotion from instinct because as a pure wave form music is principally apprehended and processed by the heart. Understanding how the heart works is vital to understanding how a dog's mind works.
The reason why we like sad music is because it triggers unresolved emotion, in particular the deeper layers of the emotional battery, and then music converts these pangs of fear (sensations of collapse) into a conductive flow of emotion and once converted into flow, the heart then can process the experience. So we like sad music because there is no such thing as a bad feeling. All feelings are predicated on a positive state of emotion, and resonating with something via a pure wave form is a state of yearning. Yearning is a state of flow. Flow is always good. While yearning can be linked very tightly to an instinctive, intellectual condition of grief, it is nonetheless not synonymous. We like sad music because unlike grief, it makes us feel good.