Bands/artists whose appeal is partly that they cover so much ground

Blondie!

Girl group pop -> power pop -> punk rock -> new wave -> reggae -> disco -> rap

I think we're losing the theme here. Artists that cover many genres out of musical desperation really don't count. It's the folks who're so incredibly musically literate that they can effortlessly hop from genre to genre convincingly ought be the focus of this exercise. I think a requirement ought be 3 good albums in 3 "reasonably" disjoint genres. 3 is a good number, 'cause that rules out Ice-T/Vanilla Ice (who I'm not disparaging, necessarily).

If you mean over a career rather than more or less concurrently, then you can add Zappa and Bowie. Lotta Zappa haters here, but you can't argue with his breadth.

Oh, damn. I forgot about Neil's Geffen-suit stuff. I'm not a big Neil lover, but I heard that record exactly once in the 80s and I've never been able to track it down. Granted, I kinda forgot about it sometime around 1995. Has that reappeared anywhere?

(And no, I wasn't picking on Neil in particular.)