Math IA about music and harmonies

Hi! I was wondering if anyone had any idea on how to expand an IA where I'm investigating harmonies and sine graphs and determining why some sounds/chords sound better than others. I just began doing the math for it and realized it is quite simple and easy and I don't think I will have much to write about. Does anyone have any suggestions on how I can expand this topic?

Hey there
I've popped your thread into extended project qualification (epq) so you might get a few more responses
Have you tried thinking also about the psychology behind why people think certain chords sound better or nicer/happier than others?
Cheese