Generally speaking we can say that most people (and animals as well) react better to harmonious music. And with that I do not only speak about pleasant in melody, harmony and rhythm, but also in the musical interval system. When "pure" intervals are used - based on the harmonic series - music is at it's most harmonic. Nowadays with the modern 12-Tone Equal Temperament we in fact are listening to "tempered" intervals that are off-pitch (false in fact) in comparison to the harmonic series.
There is much more to say about this topic, but if we get back to your question without too much detail and so, then you have to say that what "harmonious" is to one person, could be "disharmonious" to another. Some people for example for example fine up-tempo Bebop Jazz not "harmonious" sounding, some people find trash-metal or experimental electronic music pleasant to listen to, while others would call it "noise".
That's why I think that - specially when it comes to "healing music" - music should be specifically created for the individual in question. A "one size fits all" music piece for "healing purposes" is to describe the same antibiotics for any and every condition. For some people it might work, for other is might not or could even cause harm. I think "healing music" should only be written by people with knowledge of medical and mental health as well as music. Not by musicians without deeper insight the medical fields, not by medical specialists without proper knowledge about music, composition, sound engineering.
At the end music is very personal. And the more a person learns about music and explores the many styles, the better you understand it's value and importance. I personally think that every person should learn to play an instrument. That does not have to be on professional level of course, but learning about music and making music is nonetheless very important. This is why great minds such as Pythagoras obliged his students to learn about / do something with music.
Did you know that both halves of the brain are pretty much equally active with music? There isn't much a person can do that will activate the brain in the way music does.
But, I'm drifting off ... hehehe
Well, I asked for it, didn't I?
And it's better to have too many things on the "to-do" list that you can't all do, then no list at all.
Keep it coming ... and I will see what I can do with it. And if not me, then perhaps another member of this forum with skills, knowledge, insights might become inspired by it all and add to the collective knowledge base.