Q: do i just add the fourth  note in the scale to the major triad? if so what is the difference between an 11 and a 4? thanks
A: it's less about rules than you may think. it's like spelling. it's developed over time and there are some exceptions that don't make too much logical sense but that's how it's evolved. i will go through all the numbers and see if i can explain what each one probably means.