I'm not sure it's meant to teach music theory. As you observe, that would get complicated. > But then when you click the Cmaj button it only plays CGE. Becaus

I'm not sure it's meant to teach music theory. As you observe, that would get complicated. > But then when you click the Cmaj button it only plays CGE. Because those are the notes in Cmaj > Why only three notes? A chord can have more than three. Yes but not Cmaj. I don't know if you're asking these questions yourself or putting yourself in the place of someone who is learning theory - but it seems a strange criticism of a single page interactive website that it fails to explain the vast amount of arbitrary information embedded in western standard practice.