LONDON (AP) - Thousands of flag-waving fans gathered to watch British music royalty celebrate Queen Elizabeth II on Monday with a Buckingham Palace concert featuring acts from throughout her 60-year-reign. But the queen's husband, Prince Philip, missed the concert after being hospitalized with a bladder infection.
Palace officials said the prince, who will turn 91 on Saturday, was taken to the King Edward VII Hospital in London from Windsor Castle on Monday as a precaution and will remain under observation for a few days.
"I hope he's OK," said Paul McCartney, who is due to close Monday's concert. "We all send our best wishes for a speedy recovery."
Despite Philip's illness, members of the royal family including Prince Charles, his wife Camilla, Duchess of Cornwall, and Princes William and Harry sat in a royal box to watch the show, performed on a specially erected stage outside the palace.
Some 12,000 contest winners sat in bleachers, while a huge crowd stretched down the Mall, the wide boulevard leading up to the palace.
The show opened in a blaze of sound and color, as the band of the Coldstream Guards joined Robbie Williams onstage for his hit "Let Me Entertain You."
Officials said the queen would still attend the concert, which features a full hand of knights - McCartney, Sir Elton John, Sir Cliff Richard and Sir Tom Jones - along with Dame Shirley Bassey, Stevie Wonder and younger artists including JLS, Kylie Minogue and Will.i.am.
But she was attending without Philip, until now her constant companion throughout the jubilee celebrations.
On Sunday, Philip joined the queen and senior royals on the River Thames in cold and blustery weather for a pageant in honor of Elizabeth's 60 years on the throne
The prince, who married then then-Princess Elizabeth in 1947, has cut back on official engagements in recent years but still maintains a busy schedule. He spent four nights in the hospital over Christmas after suffering chest pains and underwent a successful coronary stent procedure to clear a blocked artery.
He has been at the queen's side during engagements across Britain to mark the jubilee, and appeared in good spirits as he traveled down the river on a barge Sunday, despite the harsh weather.
The palace said Philip was "understandably, disappointed about missing this evening's Diamond Jubilee Concert," as well as a St. Paul's Cathedral service and other jubilee events planned for Tuesday.
The monarch's own musical tastes are a mystery, and the Press Association news agency reported she brought a pair of earplugs to a similar concert a decade ago. According to The Guardian newspaper, the only song the queen has ever been known to request is "Some Enchanted Evening" from the Rodgers and Hammerstein musical "South Pacific."
"I don't think she's a big pop music fan," said Elton John, who paid tribute to the monarch's constancy.
"She's not trendy, she doesn't follow any fads," John told the BBC. "She's stoic, she's brilliant, she's wise, she's funny, and we're all really happy to be here."
Before the concert, 12,000 contest winners and charity workers enjoyed a jubilee concert in the palace grounds. Each received a hamper containing a meal - partly created by experimental chef Heston Blumenthal - of tea-smoked Scottish salmon, coronation chicken and strawberry crumble crunch made with fruit from the queen's Sandringham estate.
The jubilee was being marked around the world in members of the 54-nation Commonwealth of former British colonies.
The small Pacific island nation of Tonga claimed the honor of lighting the first of more than 4,200 commemorative beacons to be set alight in Britain and abroad. The queen will light the final beacon following the concert.
One beacon will be lit in Kenya at the Treetops Hotel, where Elizabeth was informed of her father's death in 1952, making her the queen.
After a drizzly, gray start, the weather looked up Monday, with a forecast of some sunshine by the time the concert starts. Despite threatening weather that turned to heavy downpours, more than 1 million people are estimated to have turned out Sunday to watch the 1,000-boat flotilla on the Thames.
Margaret Watson, 73, in the crowd near Buckingham Palace on Monday, remembered watching the Coronation on the television set which her family bought especially to watch the event.
"I am here to say thank you to the queen for all she has done," said Watson, who came to London from Yorkshire in northern England with family members. "I am just so pleased to have lived through her reign."
Others were less happy to have lived through the rain.
"I have run out of dry clothes and my sleeping bag is soaked through. My tent is ruined," said Chris Wittington, 46, from suburban Essex county, near London. "But apart from that, it has been excellent."
John is set to perform "Your Song," ''I'm Still Standing" and "Crocodile Rock." Tom Jones will pose the question, "Why? Why? Why?" in the song "Delilah," while Annie Lennox will sing "There Must Be An Angel."
Ska band Madness is expected to perform "Our House" on the palace roof, evoking a similar appearance at a Golden Jubilee concert 10 years ago by Brian May of Queen.
Kylie Minogue and Stevie Wonder will play a medley of greatest hits, and Paul McCartney will play "Live and Let Die," his James Bond theme. American soprano Renee Fleming will perform with the BBC Concert Orchestra.
The 262 residents of the remote South Atlantic island of Tristan de Cunha, a British territory 1,500 miles (2,400 kilometers) from any other land, are combining their Jubilee beacon with some environmentally conscious gardening. They are lighting their fire with invasive species including the New Zealand Christmas Tree, loganberry and other alien plants.