Why does music have an overwhelming power to almost control our emotions?
The field of study you want is psychoacoustics, more specifically music psychology, start at the reference. The brain is primarily a pattern-matching engine. It is especially optimized for order and harmony. Good music has a good balance of that in the tones, harmonic relationships, melodic order, rhythm, and so on. Good music also offers enough complexity to stimulate and interest the brain, but not so much complexity as to be perceived as disorder. Music also provides very strong associations with memories. One piece simply brings me enjoyment. Another piece equally good brings me to tears with a deep emotional response, because it stirs the memory of my daughter playing it.
