Katy Perry, Eva Longoria, Oprah, and Lady Gaga all appeared at Kamala Harris rallies on Election Eve Monday night.

Celebrities, including Oprah Winfrey, DJ Jazzy Jeff, and Fat Joe will join Harris on the steps of the Art Museum of Phildelphia for the free event in the city, which will start at 5 p.m. to 10 p.m. Harris is not expected to address the crowd till around 11 p.m.

Lady Gaga was also among the celebs on hand. Earlier in the event she performed "God Bless America," and after Harris delivered her rousing get-out-the-vote pitch, she returned to the stage for a surprise performance of her classic,