Jay-Z borrowed from Nirvana's Smells Like Teen Spirit on his new song, Holy Grail, which apparently features Justin Timberlake.  The rapper got permission to quote Kurt Cobain from Courtney Love.

Holy Grail will be a bonus track on his upcoming album, Magna Carta Holy Grail.  Spin has obtained the lyrics that Jay-Z uses from Smells Like Teen Spirit.  Jay-Z raps:

"And we all just / Entertainers / And we're stupid / And contagious."

This borrows from the chorus of Smells Like Teen Spirit, "Here we are now, entertain us.  I feel stupid and contagious."  

Jay-Z also drops Kurt Cobain's name.  In the song he says, "I know nobody to blame.  Kurt Cobain.  I did it to myself."