PHILADELPHIA - OCTOBER 4:  Musician Bruce Springsteen performs an acoustic set at a rally on the Ben Franklin Parkway in order to assist the Obama campaign's voter registration and volunteer recruitment efforts October 4, 2008 in Philadelphia, Pennsylvania. About twenty five thousand attended the free concert in support of Democratic U.S. presidential nominee Sen. Barack Obama (D-IL). Getty Images logo Getty Images 44 months ago

PHILADELPHIA - OCTOBER 4: Musician Bruce Springsteen performs an acoustic set at a rally on the Ben Franklin Parkway in order to assist the Obama campaign's voter registration and volunteer recruitment efforts October 4, 2008 in Philadelphia, Pennsylvania. About twenty five thousand attended the free concert in support of Democratic U.S. presidential nominee Sen. Barack Obama (D-IL).