Prince tipped off everybody at Madison Square Garden, including Madonna, Donald Trump, Jimmy Fallon and Leighton Meester, to a party after his concert Tuesday night. Before his last number, the rocker dismissed his backup vocalists and dancers from the stage, saying, “You all go to the after-party at The Darby. I’ll handle this last song!” The Purple One eventually turned up at midnight at the hot spot packed with Jay-Z, Leonardo DiCaprio, Questlove, Mos Def and Casey Affleck. Prince played keyboard with his opening band, Sharon Jones & the Dap-Kings, before he left at about 3:30 a.m.