Do bohemians attach more social stuff to music than, I don't know, the soccer mum who is listening to her children's choices in the car? That might explain a persistence of musical-class-thinking amongst the bohemians while it has evaporated elsewhere. (Although I guess if you went and actually ask someone about what they like, they would probably fall back on the kinds of patterns of explaining themselves in relation to the world which they had needed to develop at high school, so those patterns could be latent much more broadly.)

My friends fall into two categories: those who still listen to the same music they did at university, and don't really follow any new stuff, and don't really feel bad about this; and those who still keep up with trends, or feel they ought to be, if only to disapprove of or disparage them. The latter are closer to what people would call bohemian... I've always felt caught because I like to keep up, and have always been attracted to bohemia, but have always felt too square or straight to be part of bohemia... also I get bored of some aspects of it too easily.