"How has modern jazz survived? It is not popular or commercial. How has modern art survived? It is not popular."

Well... I think a lot of people do make a living playing modern jazz, so on that level it must be pretty commercial. And I'd wager that it's probably more popular than folk music. Not science, I know, but far more people I know have a copy of John Coltrane's 'A Love Supreme' in their collection than any folk music.

Meanwhile, try telling Jeff Koons, Damien Hirst, Tracey Emin and a host of other modern artists that modern art is not popular. Again, it's far more popular than folk music.