Someone more proficient might be able to come up with a virtual tag that you would display or navigate in place of Artist, but that still wouldn't get you around the fact that you can't tag artists with metadata so you'd have to tag each track on which the artist appears with some denotation of his or her status.
The most straightforward way is to put it in the artist name, but that would have other effects like screwing up scrobbling results and probably other unintended consequences I'm sure I'm not thinking of.