Although the royal wedding is in four days, we still don't know a lot about what's going to happen. We don't know what Kate's dress looks like, where the couple is going on their honeymoon, or really any other kind of specifics. The only true things we know at this point are: that the Queen will be there, and that Guy Ritchie, Joss Stone, Sir Elton John, David and Victoria Beckham, and Rowan Atkinson have all been invited.
But the lack of concrete facts regarding the formal nuptials haven't stopped anyone from speculating as to how crazily Prince William and Kate will celebrate after they've exchanged vows. It's been reported that the couple will throw two receptions (an official one for dignitaries and then another for their family and friends), and English publication The Daily Star claims William and Kate asked Beyoncé and Jay-Z to perform their hit song, "Crazy in Love" at the less-formal party (as a source revealed "both William and Kate are massive fans.") This rumor actually seems more probable than others that have surrounded the couple, as Englishmen and women are acutely aware of how Prince William and Kate aren't keen on adhering to ancient English traditions and have worked especially hard to make their big day more personal than some of the other more stuffy royal weddings.
Beyoncé and Jay-Z are both in Europe right now while B promotes "Girls (Who Run the World)," so chances of them dropping in on the festivities are considered especially high (as is an encore of "Bonnie and Clyde").
Source: Daily Star