Pitchfork has spotted videos of The Obamas celebrating their last Halloween in the White House on Monday. The party included kids in costumes, candy, and tributes to two pop icons, as Pitchfork spotted. President Obama, obviously enthusiastic about a Prince costume, sang a few bars of "Purple Rain," and later, tried his best to dance to Michael Jackson's "Thriller" with the First Lady. As he's proved before, the president has pipes, if not the moves. Check out the videos above and below.