Gary Barlow: the day the Prince of Wales taught me how to write a Diamond Jubilee song "He said 'If you really want the Queen to like this, find people; go and travel and find people."" Barlow said he had originally planned to compose and record the song entirely in London, but after being given inspiration by the Prince, he decided to travel to the Commonwealth countries of Australia, Kenya, Jamaica and the Solomon Islands to find guest musicians and inspiration. The final record, called Sing, features more than 200 singers and musicians, including a guest appearance from Prince Harry on the tambourine, as well as The Military Wives. The music was written with Andrew Lloyd Webber, although the lyrics came later as Barlow was travelling. He wrote the lyrics while visiting the location in Kenya at which the Queen found out she had ascended to the throne on the death of her father George VI. Barlow said: "She started her reign there and we started our record in that place. That was beautiful. The song - which features well-known musicians such as reggae duo Sly Dunbar and Robbie Shakespeare, and ska guitarist Ernest Ranglin - changed continually while Barlow was en route recording sounds. We were out in the middle of places where people made their own instruments, flutes out of bamboo and a group in Kenya that had made things out of oil tins. And it somehow all bloody worked. Barlow and Lloyd Webber visited Windsor Castle last week to play the track to the Queen, along with footage from his travels, and she was impressed with the results. As Prince Charles had predicted, she was just most interested in the people on the screen - 'What are they playing and where are they and who are they? So I told her all the stories about the people and the places and where they lived and who they were. And she loved it. The journey will feature in a BBC1 documentary Gary Barlow: On Her Majesty's Service to be screened in the coming weeks.