Singers Annie Lennox, Corinne Bailey Rae and James Morrison have been lined up to headline a concert in September calling for global peace.
The gig will be Lennox's first public appearance this year
"Something that is of common interest to every man, woman or child on the planet must surely be the notion of peace," said Lennox.
Beth Orton and Marc Almond will also perform, and David Beckham and Jude Law will record special video messages.
The Peace One Day gig will take place at London's Royal Albert Hall.
In 2001, 21 September was designated Peace Day and is recognised by the United Nations.
"I'm thrilled and delighted to be part of it, and to contribute to making Peace One Day a reality," said Lennox.
"Without peace we cannot survive," the former Eurythmics star added.
Actor Law said: "I am immensely proud to be a part of this historic project. This process is about creating an annual moment of global unity. It can only work if we all become involved and it's essential that we do."
Supporters of the project include Coldplay frontman Chris Martin, Pop Idol mogul Simon Fuller and Virgin boss Sir Richard Branson.
Tickets go on sale today priced from £35-£75.