The original flash mob that you saw in our Student Union was coordinated by an ex-dancer you was very involved on campus. She basically just sent an email to a few student organizations and athletic teams asking if anyone would like to take part in the event. We started practicing once a week about 4 months before the actual event, so it definitely takes some time (especially with everyone's busy schedules) to make it look good. The organization that Abe21599 is referring to was inspired by our original flash mob and actually had nothing to do with the Union event.