Leo has a lot of books, tried to find the one with this quote. He seems to be a very interesting writer. I'm gonna try a book or two of his. Thanks for your post, was a good subject to try a search for. Sorry have not found what your looking for, but later if I find it, will reply again.
The importance of emotion in music is one of the topics covered in the book "This is Your Brain on Music" by Daniel J. Levitin . . .