Celebrities , who gather in London to celebrate King 's 90th birthday . Mandela at outdoor concerts in his honour in London 's Hyde Park . Crowd of 46,664 . ` ` Happy Birthday '' written by Will Smith . Other guests at the concert included British Prime Minister Gordon Brown , former U.S. President Clinton , talk show host Oprah Winfrey and actor Robert De Niro . Artists include Amy Winehouse , Queen , Annie Lennox , Simple Minds .
Celebrities , who gather in London to celebrate King 's 90th birthday . Mandela at outdoor concerts in his honour in London 's Hyde Park . Crowd of 46,664 . ` ` Happy Birthday '' written by Will Smith . Artists include Amy Winehouse , Queen , Annie Lennox , Simple Minds .