Katy Perry performs “Dark Horse” at the 56th annual Grammy Awards in Los Angeles

Katy Perry performs "Dark Horse" at the 56th annual Grammy Awards in Los Angeles

Katy Perry performs “Dark Horse” at the 56th annual Grammy Awards in Los Angeles, California January 26, 2014. REUTERS/Mario Anzuoni (UNITED STATES – Tags: ENTERTAINMENT) (GRAMMYS-SHOW)