https://hornetapp.com/stories/the-entertainer-and-the-artist-the-future-of-lady-Gaga/
saw this shared by a friend in facebook so i reckon it may be worthwhile to discuss it here (let me know though if AP)
author made interesting points in explaining how Madonna was able to overshadow Cindy Lauper, the same with Britney to Xtina, and now with Katy to Gaga. To summarize it, the entertainers (Madge and Britney) tend to have longer careers and bigger popularity than the artists (Cindy, Xtina) because less is expected of them, at least in terms of talent and delivery. While those that are labeled as serious artists had high expectations on them (to which Gaga categorizes herself to) that's why when they don't deliver the expectations, they fail.
i don't understand though why he has to leave out Janet, Beyonce and Rihanna in a different category, but I guess that's a result of stereotype - that pop is more associated with white acts as r&b is to black. Sounds a little racist, but i guess that does exist in the system.