A bunch of the material available in this paper is sufficiently common knowledge to appear e.g. on Wikipedia: https://en.wikipedia.org/wiki/Equal_temperament .
The most major novelty here appears to be an attempt to hand-wave some general aesthetic principles for what humans like, and apply these to the brain via some sort of fuzzy "computational approach" (which never, y'know, broaches the point of an actual computer program). A lot of the overarching explanation can be ignored to the benefit of the theory in many cases: for example, it is likely more helpful to a neurobiological understanding of harmony to steal his insight that the minor chord probably sounds "good but off" because it has the right intervals in the wrong order, than to couch it in the author's full explanation with computational assumptions etc.