Last night, a mere week after her high stakes performance on "Today," Katy Perry returned to New York for a sold-out show at Manhattan's Hammerstein Ballroom. She wasn't alone: Cobra Starship opened the show and she was joined on stage by 3OH!3. The crowd was star-studded as well, as Perry welcomed Donald Trump, his wife Melania and Rihanna, who also joined Perry at a party at Manhattan hot spot the Griffin after the concert.