Lady Gaga appears live with U2 on stage at Madison Square Garden
In the most recent development of U2's eight-night stint at New York's Madison Square Garden, singer Lady Gaga joined the band on stage.
Joining the famed Irish rock legends in a surprise performance of "Ordinary Love," she sang a duet with Bono and played the piano.
The song was part of the soundtrack for the 2013 biopic "Mandela: Long Walk To Freedom."
A parade of celebrities has appeared for U2's performance including Sir Paul McCartney, Alicia Keys and Jon Bon Jovi.
To watch a video of the performance: http://youtu.be/OZfXckUCTWY