Musicologist Peter Hamel explores the effects of music and sound on the human psyche of Indian, Tibetan, Arabian, and of the Far Eastern techniques of vocal and instrumental improvisation, especially in religious contexts. Also included are sections on rock music, psychedelic music and drugs, mantra, the relationship of vowels to parts of the body, meditation, music therapy, breath and voice, singing and 'one's own sound.'
One of my favourite German composers discusses the many different aspects of music from around the globe and how to build an appreciation of them. A really though-provoking book which I have re-read several times over the years.
He talks about a lot of things, and is full of deep cut music recommendations from the 60s and 70s which is pretty rad.
One of my favorite things he refers to is the notion of a collective unconscious between all of us, and how music is involved with that. He talks about how music permeates the cosmos and exists in some ethereal form that musicians are able to tap into, and how the music “flows through” the artist as opposed to being created by them.
Rick Rubin talks about this same concept in his book The Creative Act and refers to it as “Source”.