Nevermind, the second album from Nirvana, launched the band's mainstream success.  It is often considered to be one of the greatest albums of all time.  The producer of the album, Butch Vig, reveals the battles he had with the band in a new interview with Rolling Stone.  Vig talks about getting Kurt Cobain to believe in his vocal tracks:

"'Kurt kept trying to bury his voice.  I kept arguing, 'You can't do that. Your vocal performance is as intense as the drums and the bass and the guitar.'"

Vig won that argument.

It's often been said that Nirvana did not expect Nevermind to blow up like it did.  But, Vig says that he knew they were on to something, even when he listened to a poor demo recording of Smells Like Teen Spirit.  Vig recalls, "The week before I flew to L.A. [to produce Nevermind], Kurt sent a cassette, which was done on a boombox.  It was really terrible sounding. You could barely make out anything. But I could hear the start to 'Smells Like Teen Spirit,' and I knew it was amazing."