Justin Bieber’s concert at Madison Square Garden Tuesday night was an all-star affair, as Usher, Ludacris, Sean Kingston, Miley Cyrus, and, um, Boyz II Men joined the Biebster for the show, which was being filmed for his upcoming 3-D biopic. According to witnesses, Cyrus’ appearance — the teenage royals dueted on Bieber’s song “Overboard†— was the one that got the crowd screeching at the highest pitch. E! reports that “the crowd went beyond wild whenever Justin and Miley made any physical contact whatsoever, however innocent.†It’s frankly pretty surprising that these two being in the same place at the same time didn’t cause Twitter to explode. [E!]