For instance, have you ever liked an artist ever since they were a completely unknown entity (i.e. not even playing shows,) and then they became either an uber-famous local artist, or a very obscure national act?
Or, for instance, you like an artist that was an obscure national act, and they became celebrities?
I haven’t, really. Although I have come within months of doing so. I got into Dashboard Confessional just as his/their first song was becoming popular, and he barely had enough people in the House of Blue to fill the first floor. Then of course they went on to play small stadiums. So, more than 1 but not quite 2 levels of fame (from low on one rung, i.e. medium sized clubs, to low-medium on another.)
Similarly with the Red Hot Chili Peppers. While they had one MTV hit awhile back, they had drifted back into relative obscurity by the time Bloodsugarsexmagick came out. I got into them right as Give It Away came out, and they did become celebrities, but by the time I got into them they were almost at stardom already.
ETA: One more example, Blink 182, I would count them as having risen 2 levels since Dammit came out. But since that’s the only song I like by them, I don’t think they count either.
Unfortunately, none of my favorite completely obscure or local or opener bands have become any more famous than when I first liked them