And C3 doesn't exist either. The NRS classification is based, not on intellect, but occupation. I'm not sure where folk-singers fit in.
Grade A; Social class - upper middle class; Chief income earner's occupation - higher managerial, administrative or professional Grade B; middle class; intermediate managerial, administrative or professional Grade C1; lower middle class; supervisory or clerical and junior managerial, administrative or professional Grade C2; skilled working class; skilled manual workers Grade D; working class; semi-skilled and unskilled manual workers Grade E; non working; casual or lowest grade workers, pensioners, and others who depend on the welfare state for their income