The first article in the Playing Changes series helped you visualize and hear melodies by thinking in scale degrees. This concept also applies to hearing tonal harmony.
My friend and colleague Leah Pogwizd uses with a hybrid notation that incorporates standard notation, roman numerals, and scale degrees. This notation will help you visualize tunes functionally, which makes it easier to transpose music into 12 keys.
Check out Leah’s notation for Milt Jackson’s Bag’s Groove: (Note that “L b7” means b7 below scale degree 1.)