Mob events like this are great.
Sound of Music Station
One thing we despise about traditional musical performances, is the way the performers are up on a stage isolated form the audience. Of course this is usually necessary, but... We always love it when the performers work to tear down that barrier. (performers going out into the audience, or bringing the audience up on stage, singing, clapping, stomping with the performer, theater in the round....)
The ultimate perfection is what is occurring here. Everyone is the same, on the same level, and intermixing, and the more people join in and intermix the better. Sure, it is obvious that many of them have practiced, but this is hidden as much as possible so that it doesn't separate the practiced from everyone else.
Other Great Examples:
T-Mobile has sponsored events like this, and they show how everyone is phoning someone about it or taking pictures. Their catch phrase is so morally true and brilliant:
"Life is for sharing"