The Duke of Cambridge with his brother Prince Harry, right, pointing at something as they attend the Diamond Jubilee concert in London Monday June 4, 2012. (AP Photo / Dave Thompson, Pool)

FILE - A Sunday June 3, 2012 photo from files showing Britain's Queen Elizabeth II, and her husband Prince Philip watching the proceedings from the royal barge during the Diamond Jubilee Pageant on the River Thames in London. Buckingham Palace says Prince Philip, husband of Queen Elizabeth II, has been hospitalized with a bladder infection. The 90-year-old prince has been taking part in celebrations of the queen’s Diamond Jubilee. (AP Photo/John Stillwell, Pool, File)

Singer Robbie Williams performs at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Jessie J performs at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Annie Lennox performs at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Grace Jones performs at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Gary Barlow and Cheryl Cole perform at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Will.I.am and Jessie J perform at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Cheryl Cole performs at the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

Spectators along the mall prior to the Queen's Jubilee Concert in front of Buckingham Palace, London, Monday, June 4, 2012. The concert is a part of four days of celebrations to mark the 60 year reign of Britain's Queen Elizabeth II. (AP Photo/Joel Ryan)

A member of the public wears a hat showing Britain's Queen Elizabeth II before the start of a pop music concert at Buckingham Palace to help celebrate Britain's Queen Elizabeth II's 60-year reign during Diamond Jubilee celebrations in London, Monday, June 4, 2012. (AP Photo/Tim Hales)

People with face masks of Queen Elizabeth II, center, Prince William, left, and Kate, Duchess of Cambridge enjoy a street party in Sutton, south London to celebrate the Queen' Diamond Jubilee. (AP Photo/Sang Tan)

People enjoy a street party in Sutton, south London to celebrate the Queen's Diamond Jubilee, Monday, June 4, 2012. Britain's Queen Elizabeth II is to attend later Monday a concert and to light a national beacon outside Buckingham Palace as part of a four-day Diamond Jubilee celebration to mark the 60th anniversary of Queen Elizabeth II accession to the throne. (AP Photo/Sang Tan)