I think they mentioned the weather because it's relevant to his reputation as a legendary live performer and it's part of a great story. [1] There's something almost magical about incredible live performances. I can't really describe it, but sometimes a show has the perfect mix of emotion and artistry and it's completely mesmerizing to be a part of, even as a spectator. Participating in that moment bonds millions of people together in a small way. Even if they have nothing else in common, they were able to experience that together. Prince's Superbowl performance was one of those moments.

[1] http://www.maxim.com/entertainment/prince-2007-super-bowl-pe...

It's a poorly written sentence, but it's also fairly clear what they meant to say. It's polite to give people the benefit of the doubt.

I've reworded the sentence in the post—does it work better that way? Many thanks for the feedback, everyone. :-)

Thanks, I really do appreciate it. The thought that it could have meant televised audience never crossed my mind and surely wouldn't have for some other portion of the audience as well. I was out googling for largest concert size records to make sure I wasn't crazy.

during the set he performed purple rain, probably his most famous song, and it was pouring down rain. that's why the weather is notable.

a hundred million people in one venue is certainly an unbelievable number though.