Katy Perry and Lady Gaga. Friends ... “Teenage Dream” (2010) 19 million album equivalents, per Chartmasters Gaga: “The Fame”/”The Fame Monster” (reissue) (2008, 2009) 35.6 million ...

Katy Perry has gushed about fellow pop star Lady Gaga. The California Gurls hitmaker ... In support of her latest album, Mayhem, the Die with a Smile hitmaker will kick off her Mayhem Ball tour ...

Katy Perry is singing the praises of fellow pop superstar Lady Gaga after catching her ... track "Perfect Celebrity," off her latest album MAYHEM. Gaga's stop in Mexico City follows her headlining ...

Katy Perry took a break from her own tour to show some love for Lady Gaga during a ... incredible response to the new album inspired me to keep things going," Gaga told fans on Instagram in ...

Kevin Mazur/Getty Katy Perry joined in on the Viva La Mayhem fun! On Monday, April 28, the "Teenage Dream" singer shared pictures and videos from Lady Gaga's Sunday night concert in Mexico City at ...

Katy Perry loves sharing her woman’s world with Lady Gaga. In the crowd at Mother Monster’s ¡Viva La Mayhem! concert in Mexico City Saturday (April 26), the “Firework” singer was one of ...