Elton John sang "I'm Still Standing," Stevie Wonder crooned "Isn't She Lovely," and Paul McCartney sent "All My Loving" as musical royalty celebrated Queen Elizabeth II's 60-year reign with a concert outside Buckingham Palace on Monday. But the joy was tempered by news that the queen's husband, Prince Philip, had been 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.

As the Diamond Jubilee show ended, Prince Charles took the stage and encouraged concertgoers to make some noise for his father. The crowd responded with a roar and chants of "Philip."

The heir to the throne paid tribute to his mother, addressing her as "Your Majesty — Mummy" and leading the crowd in three cheers for the monarch.