I've been getting started with Sheets of Sound and as I've mentioned already a few times I just love it. It's got me thinking that I need to improve other areas of my playing and general musical knowledage as well. I'm looking for suggestions on some good books that get into a study of jazz chords and progressions. I haven't studied jazz seriously since the early 90's, and even then I didn't stick with it long enough for it to really sink in as much as I'd like it to. I do have a Real Book and a few dozen other jazz standards that I read through occasionally, but I'm looking for something that gets more into theory and analyzation of the progressions. Anybody have some good suggestions? Thanks!