Jay-Z performs at an Obama rally in Ohio, one day before the election, November 2012.

See more: The Best of 2012: The Year in Music

Bruce Springsteen performs at an Obama rally in Ohio on November 5th, 2012, one day before the election.

Kid Rock performs during a campaign rally for US Republican Presidential candidate Mitt Romney at Red Rocks Amphitheatre in Morrison, Colorado, October 23, 2012.

Katy Perry performs at a campaign rally for President Barack Obama at the Delta Center on November 3, 2012 in Milwaukee, Wisconsin.

Meatloaf watches as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Defiance High School on October 25, 2012 in Defiance, Ohio.

September 18: Jay-Z and Beyonce host an exclusive fundraiser for Barack Obama's campaign at the 40/40 club.

Presidential candidate Mitt Romney sings 'God Bless America' with singers Randy Owen, John Rich and Big Kenny during a rally at Defiance High School, in Defiance, Ohio, October 25, 2012.

Bruce Springsteen and his wife Patti Scialfa disembark from Air Force One at Rickenbacker International Airport as they arrive in Columbus, Ohio, on November 5, 2012 to perform at a campaign event for President Barack Obama.

President Obama met up with No Doubt backstage at "The Tonight Show With Jay Leno" after they performed on the L.A. show on October 24, 2012.

Trace Adkins performs before US Republican presidential candidate Mitt Romney speaks at a campaign rally on October 4, 2012 in Fishersville, Virginia.

Stevie Wonder warms up the crowd during a campaign rally for President Barack Obama at Fifth Third Arena November 4, 2012 in Cincinnati, Ohio.

American singer Taylor Hicks performs at the Tampa Bay Times Forum in Tampa, Florida, on August 30, 2012 on the final day of the Republican National Convention.

Katy Perry performs at a campaign rally for U.S. President Barack Obama at Doolittle Park on October 24, 2012 in Las Vegas, Nevada.

Lee Greenwood sings at a campaign rally for Republican presidential candidate former Massachusetts Gov. Mitt Romney at Tidewater Community College on October 17, 2012 in Washington, DC.

Marc Anthony speaks during a campaign rally with First Lady Michelle Obama to grassroots supporters at James L Knight Center on November 1, 2012 in Miami, Florida.

Kid Rock and Congressman Paul Ryan attends the Congressman Paul Ryan Rally With Kid Rock at Oakland University Athletic Center on October 8, 2012 in Rochester, Michigan.

Pearl Jam's Eddie Vedder performs at a private Obama fundraiser in Tampa, Fla. (Photo by Andrew Weinstein, Twitter.com/Weinsteinlaw.)