Fourth of July performances

Kris Connor/Getty Images for Capital Concerts

Megan Hilty performs during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

Barry Manilow performs during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

Neil Diamond performs during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

Tom Bergeron speaks during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

Members of "Motown" perform during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

Jackie Evancho performs during "A Capitol Fourth 2013 Independence Day Concert" on the west lawn of the U.S. Capitol on July 4, 2013, in Washington.

John Mayer performs with The Roots at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Ahmir "?uestlove" Thompson of The Roots performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Ne-Yo performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Hunter Hayes performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Grace Potter performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

J. Cole performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Jill Scott performs at the "Philly 4th of July Jam" on July 4, 2013, in Philadelphia.

Miguel, left, and Mariah Carey rehearse for their performance during the "Macy's Fourth of July Fireworks Spectacular" in New York.

Selena Gomez rehearses for her performance during the "Macy's Fourth of July Fireworks Spectacular" in New York.

Tim McGraw rehearses for his performance during the "Macy's Fourth of July Fireworks Spectacular" in New York.

Actor Zachary Levi, left, and Nick Cannon during the "Macy's Fourth of July Fireworks Spectacular" in New York.