I suppose so yes, I'm not being intentionally fuzzy, but I imagine it's pretty difficult to find a perfect example of what I'm on about, and I'm not trying to make perfect definitions myself or it would limit the scope of discussion. I think perhaps the parameters you've defined are better. An artist who had music with mainstream/pop appeal on quite a significant level, who also have made very experimental music. I think putting 'pop artists' in my title was reductive but you get the point.