I think that existential-phenomenology might be a useful methodology. Existential-phenomenology explores experiential phenomena from the perspective of those who experience the phenomena. This method provides a rich and thick understanding of experiences that far surpasses anything that can be gained from traditional quantitative methods.
I think it would be interesting to capture audiovisual manifestations of music in a quantitative way (as data), and determine if that quantitative data is associated with experiential data captured on the same music. I am not sure, but my feeling is that this area of research is underrepresented, which is unfortunate because music influences our lives in so many ways.