Finally bought it. It's a download PDF, but it's such a nice and compact book of theory. I don't think I have anything like it in terms of a one-stop-shop for learning (and re-learning!) theory in order to play well with others.

There's a 60% of sale on it right now - I just bought it for 50% off but I don't regret him getting a little bit more of my money. His "What Makes This Song Great?" series is my favorite thing to watch on the internet, and it's always eye opening to see and hear him play all of the parts (except drums) to most of these songs, and break down why the bits and pieces work to make you smile from a music theory standpoint.

For woodshedding and the why behind it, this will serve you well.