Beside collaborating with each other, Beyonce Knowles and Jay-Z also hooked up with Chris Martin and Kanye West respectively.
Beyonce Knowles went to Las Vegas for New Year's Eve celebration. She joined her rapper husband Jay-Z and good pals Chris Martin and Kanye West for live performances at the grand opening of The Cosmopolitan, a $3.9 billion hotel on Sin City's famous Strip.
Beyonce made a duet with Jigga in "Forever Young", and also joined forces with the Coldplay rocker in "Halo". Both of the men then supported Kanye when the G.O.O.D Music artist rapped his "Homecoming". Another performer was John Mayer who strummed his guitar as Jigga spat his "99 Problems".
Celebrities spotted off stage watching the star-studded show were Chris' wife Gwyneth Paltrow, high-profile couples Cameron Diaz & Alex Rodriguez, and Jennifer Lopez & Marc Anthony, as well as actresses Ellen Pompeo and Blake Lively.