Adapt or perish. The millenials don't care about owning music any longer, they just want access to it. They also don't care about owning movies on DVD and only buy video games on physical discs because that's the only choice. They aren't wrong, it's just their world revolves around portability and doesn't revolve around owning stuff, they prefer to spend their money going out and doing things instead of accumulating a library of crap to store in their apartments. It's a different world and the old one is not coming back.
Musicians will just have to find other ways to make money from them, a new business model, because the old model is dead and buried.