Rihanna and Jay-Z are the headline acts for what's expected to be a music festival of epic proportions, leading up to the London 2012 Olympic Games. 

Jay will take the stage on June 23, the first of the two-day BBC Radio 1 Hackney Weekend 2012 showcase.  RiRi will perform on June 24 of the festival, which takes place just one month before the Olympic Games.  Other headliners include Jessie J , Florence + the Machine ,  David Guetta , B.o.B , Trey Songz , Sean Paul , and Tinie Tempah

Organizers tell  BusinessWeek.com that the "London 2012 Festival will be the biggest cultural celebration in our lifetime."  An estimated 100,000 fans are expected during the highly anticipated Hackney Weekend, according to the website.

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