Lady Gaga + More Perform at KIIS FM’s Jingle Ball ShowLady Gaga + More Perform at KIIS FM’s Jingle Ball ShowOn Friday, Dec. 3, Lady Gaga, David Guetta, Gym Class Heroes, Taio Cruz, Flo Rida and Sean Paul performed at KIIS FM’s Jingle Ball concert in Los Angeles.Cristin MaherCristin Maher