According to Wikipedia, a flash mob is;
“A large group of people who assemble suddenly in a public place, perform an unusual and pointless act for a brief time, then disperse. The term flash mob is generally applied only to gatherings organized via telecommunications, social media, or viral emails. The term is generally not applied to events organized by public relations firms, protests, and publicity stunts.”
In that case perhaps this isn’t a flash mob since it was organised to promote a photography company, it is however very good and well worth a look. The ‘mob’ are the ‘Chorus Niagara’ singing the Hallelujah Chorus in a food hall. At the time of posting it had over 3,000,000 hits on YouTube and I first saw this on the Cranmer blog.
It will make you smile.