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US pop group The Scissor Sisters and Senegalese singer Baaba Maal are among the stars who will take part in a music festival in London in the build-up to the 2012 Olympics.

River of Music will feature acts from five continents on six stages at different sites along the River Thames.

US jazz great Wynton Marsalis and vocal group Naturally 7 will also take part.

The event will be held on 21 and 22 July, the weekend before the Games begin. More names are to be announced.

Tickets will be free and details of the ticketing arrangements will be announced in May.

Ruth Mackenzie, the Cultural Olympiad and London 2012 Festival director, said: "Of all the ideas we have had [for the London 2012 Cultural Olympiad], it is probably one of the most ambitious and, I think, the biggest.

"The idea that we can work with musicians from across the world and engage... is just simple and gorgeous.

"This is a project of incredible scale. It is a chance for artists to share and collaborate, to get beyond the playlist and enjoy a bit of Olympic magic."

Music from Europe will be heard at stages in Trafalgar Square and Somerset House, the Americas will be at the Tower of London, Asia in Battersea Park, Africa in Jubilee Gardens and Oceania in the Greenwich Old Royal Naval College.