[globnomulous]

Both terms are flexible, sure. And I agree that debating definitions is boring.

> The point is that the guy was a genius.

Is that the point? Are we discussing the man himself, or are we discussing his work? Both, I guess, according to the following:

> He’s written some of the best songs ever by many definitions. That makes him a genius.

It doesn't. Genius is a capacity, not an accomplishment. One can be a genius without accomplishing anything, and one who isn't a genius can do high-level, history-making work.