06/28/2010 01:50 am ET Updated Dec 06, 2017

SF Pride Flash Mob: Group Performs 'We Go Together' From 'Grease' At Gay Pride Festival (VIDEO)

Flash mobs and outdoor festivals go together.

As San Francisco celebrated its 40th annual Pride Festival, a large group descended with a well prepared routine -- "We Go Together" from the classic movie musical "Grease."

According to an item on, the mob practiced on Saturday and performed on Sunday. A Craiglist ad showed that there were several rehearsals, some of them mandatory.