Are you interested in jazz theory and what scale to play over what chord?

Answer 1

"Jazzology" (published by Hal Leonard) is the #1 best-selling Jazz theory book on the planet.

I am a credited contributor to that book.

The "Jazz Theory Book" by Levine is not bad, but "Jazzology" is better because it is designed as a coursebook.

Answer 2

Yes. The craziest part about jazz theory is when you can actually play more than 1 scale over the same chord; especially with dominant chords.

Jazz players/theorists have mostly developed their theoretical knowledge through experience and expertise as performers and improvisers. This is why, specifically with jazz theory, it is always important to consult the right sources/people for it, in order to understand the different variables of chord-scale theory. I would not have gotten such an assured knowledge of jazz in the ways that I know it if it wasn't because of some of my teachers at college, who in my opinion happen to have world-class levels of expertise, performance, and experience.

Probably the most reliable written source today may be the "Jazz Theory Book" by Mark Levine.