Support WBUR'Flash' Is The Key To A Joyful Mob's SuccessPlay05:00Download AudioMark MemmottDecember 20, 2010 ShareA "flash mob" gathered in a Kansas City mall on Dec. 19 to surprise visitors with a rendition of the "Hallelujah Chorus." (KansasCity.com)
A "flash mob" gathered in a Kansas City mall on Dec. 19 to surprise visitors with a rendition of the "Hallelujah Chorus." (KansasCity.com)