Jubilee concert will have 'few surprises', says Gary Barlow
4 June 2012 Last updated at 14:43 BST
Large crowds are arriving for a concert outside Buckingham Palace - which is part of the Diamond Jubilee celebrations.
Gary Barlow helped organise the concert and co-wrote 'Sing', the Diamond Jubilee song.
He told the BBC's Emily Maitlis that the musicians taking part in the concern span the Queen's whole rein as monarch.