A definition needs to be qualitative, but it doesn't need to be quantitative. How do you measure "melancholy" or "a thumpin' beat"? > if there is science to it

A definition needs to be qualitative, but it doesn't need to be quantitative. How do you measure "melancholy" or "a thumpin' beat"? > if there is science to it then you should also be able to define concrete test cases This is a misapplication of "science". Science is robust observation, not the algorithm behind something. And there certainly doesn't have to be concrete test cases for something to be "science" - a classic example is case studies and low n studies in medicine. Another is everything we've learned from brain injuries. Science isn't limited to just finding against the null hypothesis.