Stars galore join Justin Bieber

Justin Bieber promised fans "more surprises than ever" during his show last night (August 31) at Madison Square Garden. And, boy, did he deliver.

The young Canadian phenom has been feeling under the weather of late with an undisclosed illness. But he appeared in top form at the show. He predictably posted a Twitter message just before it all started: "IM HYPED!!! MADISON SQUARE GARDEN!!!!"

Miley Cyrus, Usher, Ludacris, Sean Kingston, Boyz II Men and Will Smith’s son, Jaden Smith, all made guest appearances throughout the sold-out event.

Boys II Men dedicated their song, On Bended Knee, to Justin Bieber’s mom. Usher came on stage during his protégé’s rendition of Somebody to Love. Cyrus performed a duet with Bieber and the crowd reportedly went wild as they sang Overboard.

The concert was filmed for an upcoming 3D film on Justin Bieber’s life and meteoric rise to fame. Bieber told the audience: "New York City, are you ready to have some fun? I’m filming good. We’re shooting the movie."