When I first read it I was thinking how I wish I had been a part of one, and how cool it would be. Then a couple of days later, I realized that I kind of have been... Kind of. Depends if you want to classify it as a flash mob or not...
Maybe, to make it easier I should just say that the post reminded me of some occasions, write about those occasions and leave it at that...
When I studied music, there was this room where most of the music students would spend their lunch breaks and free periods. Sometimes someone would get their instrument out and start playing a song, just to practice for class or a concert. Sometimes when this happened, other people in the room would get their instruments out an start playing as well, or start singing.
Other times, the person that started playing wouldn't even be playing a song, they would just be improvising, and other people would still join in.
I guess these aren't the best examples. Especially since we were all studying music. But I've got another example.
Last summer, one of my best friends got married. At dinner there were only close family and friends, but after dinner, more friends came, so there were quite a lot of people when the dancing started. My friend had a live band, made up of the friends that could play instruments. Since they were friends and not only there to play, they sat down with the rest of the guests sometimes and had some cake, coffee, drinks etc. While they were sitting there, they would start playing their instruments again, not for people to dance, but just to play.
Hmmm... I guess these were more like real life musical moments than flash mobs. But it sure was fun. Especially the wedding!