POPSUGAR Celebrity John Mayer Slide Photo of John Mayer Performing at Hard Rock Cafe London Rock Out by Celebrity 1/12/10 0 Shares Like us on Facebook Sign up for our daily newsletter > John Mayer performed at the Hard Rock Cafe in London on Monday. Image Source: WireImage Read More HotJohn Mayer John Mayer Katy Perry and John Mayer Break Up . . . Again Personal Trainer to the Stars Harley Pasternak Shares His Secrets The Most Surprising Celebrity Sex Confessions John Mayer Dreams Up Justin's Cookie Dough Almond Butter POPSUGAR, the #1 independent media and technology company for women. Where more than 75 million women go for original, inspirational content that feeds their passions and interests. Get the scoop with our daily newsletter TV Young Hollywood A-Listers Movies Sign up with By signing up, I agree to the Terms and to receive emails from POPSUGAR.