National TV Broadcast: Black Eyed Peas performed "I Gotta Feeling" and officially opened Oprah’s 24th Season (2009-10) along with 21,000 fans dancing on Michigan Avenue (Chicago, IL) on Tuesday, Sept 8th (2 days before it aired nationwide).   The producer, Australian Michael Gracey, was also responsible for a famous flash mob dance at a Liverpool train station that was used for a phone commercial, but Tuesdays event was much larger in scale. And in order to pull it off, late last month local casting agencies were enlisted to look for dancers. This is being touted as the World's Largest 'Single-City' FLASH MOB event ever held, thanks in part to T-Mobile! Watch in HD Quality if available. (Lyrics) I gotta feeling that tonights gonna be a good night, That tonights gonna be a good night. Lets live it up. I got my money, Lets spend it up. Go out and smash it. Like Oh My God, Jump off that sofa. Lets get get OFF, I know that well have a ball, If we get down, And go out, And just loose it all. I feel stressed out, I wanna let it go, Lets go way out spaced out, And loosing all control. Fill up my cup, Mozoltov, Look at her dancing, Just take it off. Lets paint the town, Well shut it down. Lets burn the roof, And then well do it again.