Take That's Gary Barlow is teaming up with musical maestro Andrew Lloyd Webber to create a song for the Diamond Jubilee celebrations.
And the pair are aiming to Rule The World by scouring locations around the globe to find other artists to perform with them.
The song will be performed at the star-studded Diamond Jubilee Concert in front of Buckingham Palace on June 4.
And in preparation, Barlow will embark on an epic journey around the Commonwealth to discover what the Queen means to ordinary people. The star's trip will feature in an hour-long documentary to be screened by BBC1.
Barlow and Evita composer Lloyd Webber will also aim to incorporate different musical traditions into the song which will feature artists and contributors from the UK and Commonwealth. They could include international names and unknowns from remote villages.
Barlow's journey will see him travel to the Caribbean, Africa, the Pacific Islands and Australasia.
He said: "This is probably the biggest challenge I've ever taken on musically. I'm so excited and thrilled to be a part of it."
And Lloyd Webber - who is launching an ITV talent hunt for a star for his production of Jesus Chris Superstar - said: "It is a huge honour to be involved in this historic occasion and I am looking forward very much to working with Gary."
The song-writing project was announced on Radio 2's Chris Evans show.
Barlow is helping to organise the June concert - which has now attracted more than one million ticket applications - featuring performances by Sir Paul McCartney and Sir Elton John. Others due to take part are Dame Shirley Bassey, Jessie J, Ed Sheeran and Sir Cliff Richard.