m ted, sorry but if I go into a greengrocers and ask for potatoes ,Iexpect to get potatoes not tomatoes.
If I go to an evening of jazz I expect just that, not an evening of classical Music.
If i go to a folk club I have a fairly good idea of what to expect, PARTICUARLY IF THE ORGANISER CLARIFIES FURTHER eg contemporary singer with guitar etc.,personally I prefer Home made music   to the term Folk,    but we all know what folk music is APPROXIMATELY [even if its hard to define]FROM BLUES TO SEAN NOS it is quite a broad church.