We have to be able to understand how to put the puzzle pieces together in jazz. How can you expect to do this without understanding where they go? Well, you can't! This is why Diatonic Harmony is so important. Diatonic Harmony is the road map to explain how chords and progressions fit together. Without learning this you will be completely lost as we continue to progress. Diatonic Harmony is the relationship of chords to a scale and certain key. Pretty easy once you get into it! Leave your questions in the comments section and I'll be happy to help.