CBS Class Gift - flash mob! Video of CBS Class Gift - flash mob! 2012 0 A surprise class gift to the Class of 2014 at Columbia Business School from the Class of 2013. The idea was hatched last summer. It features music the first-years used for their Happy Hour cluster entrances in September 2012. Tags: CommunityStudent LifeFlash MobHappy HourClass of 2013Class of 2014View the discussion thread.