What's a Melodic Axis? In this episode I talk about something that is also commonly called "Guide Tones", a look into how all the diatonic-jazz harmony can mostly be traced by its intervals of 3rds and 7ths, allowing us to use such intervals as a framework for voice leading the chords. You can experiment with that and realize you can pretty much only play those intervals in the progression and it will still hear how the harmony is moving. Enjoy!