Healing powers of music

I have known some wonderful people in my life who have been art therapists and never quite understood what it is they do. They say they use dance, painting, music to help heal their clients, but it seems obscure. This video, "Hitting the right note: the orchestra helping stroke survivors recover", illuminates how music can heal.

The project shown in this video tool place in 2015, but it was nice to read the work has continued.