The best work happening in this area is by a Princeton professor named Dmitri Tymoczko [1]. He's discovered some pretty fundamental results that tie together a lot of the previous theories of harmony based on geometry. He was the first music theorist ever published in Science [2] and he wrote an amazing book called A Geometry of Music [3] (technical but readable, a must for anyone trying to really understand why music sounds good).
He also teaches a 2-semester intro level music class at Princeton that is infused with his ideas, and makes the lecture notes available online [4]. Those notes are so good they're better than any intro music textbook I know of, especially for us geeks who like to hear the scientific explanation for everything.
[1] http://dmitri.mycpanel.princeton.edu/bio.html
[2] http://dmitri.tymoczko.com/sciencearticle.html
[3] https://www.amazon.com/Geometry-Music-Counterpoint- Extended-Practice/dp/0195336674