>>22988569>i like keychanges, but i only really use them when the section changes entirelyThat's modulation. When keychanges happen within a single phrase it is called multipolar tonality(according to a japanese harmony book author).
In classical music they use the sharp 7th to create a leading tone since it creates a bigger pull towards the tonic in minor it's pretty useful. It's also why japanese music use them also.
>is a tier of fucked up i don't entirely get yetIt's a bit abstract, but it's not too bad. Basically certain groups of tones leads towards one tone. That's why we have Tonic, subdominant, dominant. Subdominant leads to dominant, dominant leads to tonic. Tonic is the most stable because usually the entire scale creates a pull towards the tonic. That's why the major scale is so successful and useful.
To make key changes you have to pull towards a different tone.
In coltrane changes you have 3 different keys. Coltrange uses the V - I because it creates a really strong pull. Then he uses ii - V - I (common jazz progression) through these 3 different keys. So you get pulled into these 3 different tonalities.
Pic related also is pretty useful.
"Structural function sof harmony" by arnold schoenberg. Basically certain set of notes(chords, melody), can either imply one tonality, or be ambigious depending on which notes.
