• MEN IN BLACK photo | Jay-Z, John Mayer

Credit: Kevin Mazur/WireImage

Published: Saturday January 01, 2011 15:00 PM EST

2011

MEN IN BLACK

John Mayer joins the party onstage, performing with Jay-Z and Coldplay at The Cosmopolitan bash. The Grammy nominee – a surprise guest – landed into Las Vegas after taking a holiday road trip with friends.