Well, maybe I will let Morrissey weigh in on "popular music." He is always enlightening and quotable. And isn't it empowering, significant and liberating, if you can define things the way you want to define them?
"To me popular music is still the voice of the working class, collective rage in a way, though seldom angst ridden. But it does really seem like the one sole opportunity for someone from a working class background to step forward and have their say. It's really the last refuge for articulate but penniless humans."- Morrissey (1984)