This site is nice https://www.musictheory.net/lessons https://www.musictheory.net/lessons Music theory is not inherently complex, but the notation adds inciden

This site is nice https://www.musictheory.net/lessons https://www.musictheory.net/lessons Music theory is not inherently complex, but the notation adds incidental complexity -- it's sort of like the QWERTY keyboard; once you're stuck on a suboptimal way of doing things it's hard to move off.