Janet Jackson paid tribute to her late brother Michael, singing "Scream." Katy Perry performed with Aerosmith's Joe Perry. Taylor Swift went from singing in the New York City subway system to the top of a taxi outside Radio City Music Hall. Lady Gaga delivered a Phantom of the Opera-style performance of "Paparazzi." Beyoncé did her "Single Ladies" dance and Pink, while singing her hit "Sober," even performed on a trapeze.