The same dynamic that propped up blacksmiths, potters, tailors, etc.: the absense of scaling/automating technology. There is still demand for authentic artisanal crafts and the "good feeling" that these people can earn money, but the magnitude has been reduced to the farmer's markets.

I can see a similar thing playing out with music. There will still be some token demand, but people will not pay the same when they can have a magic, infinitely producing on-demand, tailored-to-their-taste music machine, at vanishingly small marginal costs.