London 2012 officials are keen to keep the details of the Olympic closing ceremony on Sunday secret.
Various performers have announced they will be taking part, but the BBC reports the organisers refuse to confirm any participants.
The event, which begins at 9pm (BST) on Sunday, is likely to be watched by a capacity crowd 80,000 at the Olympic Stadium, and a global TV audience.
It will be called ''A Symphony of British Music.'' Artistic director Kim Gavin said months ago the programme would span music from "Elgar to Adele".
The BBC reports the cast will mainly comprise more than 4000 volunteers including around 400 children.
The flags of Greece, Britain and Brazil, which holds the 2016 Olympics, will be raised and International Olympic Committee president Jacques Rogge will declare the London Games closed.
At the end of the ceremony, the Olympic flame, which has been burning in the stadium since the Games opened on 27 July, will be extinguished.