Photo: Jay-Z and Alicia Keys perform before the New York Yankees play the Philadelphia Phillies in game 2 of the World Series at Yankee Stadium in New York - NYP20091029103

Jay-Z and Alicia Keys perform before the New York Yankees play the Philadelphia Phillies in game 2 of the World Series at Yankee Stadium in New York City on October 29, 2009.

Jay-Z to Perform at World Series

World Series kicks off Wed., Jay-Z predicts Yankees take it in 7, singing 'Empire State of Mind'w/ Alicia Keys

Jay-Z and Alicia Keys perform before the New York Yankees play the Philadelphia Phillies in game 2 of the World Series at Yankee Stadium in New York City on October 29, 2009.

Jay-Z, Alicia Keys rock Yankee Stadium

Jay-Z, Alicia Keys rock Yankee Stadium

Photo: Jay-Z and Alicia Keys perform before the New York Yankees play the Philadelphia Phillies in game 2 of the World Series at Yankee Stadium in New York - NYP20091029103

Jay-Z and Alicia Keys perform before the New York Yankees play the Philadelphia Phillies in game 2 of the World Series at Yankee Stadium in New York City on October 29, 2009.

Jay-Z performs with Alicia Keys before Game 2 of the Major League Baseball World Series between the New York Yankees and Philadelphia Phillies Thursday, Oct. 29, 2009, in New York. (AP Photo/David