If you really care about intonation, this is the book for you. And if you're like me, an amateur musician who cares a little about intonation, but is also fascinated by the science of harmony, this is the perfect book for you. But if none of that sounds interesting, don't bother, because that's all that's here.
Clearly this author has a thesis and is trying to support it, trying to steer us in one direction on the tuning/temperament debate, but in the mean time we get a bunch of really interesting history of music theory. This is necessary because the argument for equal temperament is somewhat historical, saying this is what's been done for a very long time, and the author is saying that no, it's not been more than 100 years or so that equal temperament has been the norm, and it shouldn't be the norm now.
So a great little read, short and sweet, with lots of history. Discussing this will really make you sound like a nerd at the next string quartet concert you go to.