Some people have a belief that music has an ability to cure illness. Illness in the sense, they can cure some psychology based diseases. It will be better if I use the word phobia or mania instead of disease.
I personally do not think that music can "heal" things. It might be true with some cases. But it is just a probability fact. It is as simple as an event and cause effect. Those who strongly believe that music will heal their disease, it will cure. This applies to dysentery pills too.
You can even take dysentery stopping pills to get rid of headache and you know what? Those will works. This is just because of the confidence he / she had with the particular "curing medium".
I have read in an article that music gives sooner cure for mentally retarded people and people who are all affected with autism. In particular, piano and violin music and some wind instruments like flute, saxophone gives a better remedy.
The issue here is not to debate whether music heals or not, if it really helps the society to bring a better society, we can go for it. Other wise, screw it...