Modal interchange is the hidden framework behind how harmony works in most popular music. Most musician stumble upon it piecemeal. Modes are usually taught in a shallow way, as an afterthought. But nobody has documented the whole system.
This is that documentation.
This is not another online music theory 101 course, it's not tips and tricks. On this site I'm building the complete, systematic documentation on modes and modal interchange, and how they work in modern music, starting with the fundamentals. It's a work in progress, and it'll be built up over the course of 2026.