What exactly did Krist Novoselic say when Kurt Cobain first played him the
riff from "Smells Like Teen Spirit?"

(From what I recall reading at one point, it was something like,
"You've got to be kidding me.")

Shalom softjeans,

I suggest you to contact the manager of : http://www.novoselic.com/
She a BIG fan and knows Krist personally.

Here's an article about the song and the reactions to it:

http://www.nirvanaclub.com/get.php?section=articles&file=12.07.00.html

Hope I helped,

Levia,
Israel