Flash mob Tommy

My dear friends niece was part of this flash mob in San Francisco. I had never heard of a flash mob before. According to Merriam Webster a flash mob is a group of people summoned by e-mail or test message to a designated location at a specified time to perform an indicated action before dispersing. This event reminds me of how a musical is on film. The actors break out in song and dance and then go back to there normal routines.