Flashmob Carmina Burana

1-Where is taking place this flashmob?
2-What instrument is playing in minute 1:22?
3-How is the reaction of the people in the beginning?
4-In minute 2:14, what instrument begin to play?
5-What happens in minute 2:44?
6-Why do you think in minute 3:06 a woman is touching his chest area and at the same time she is smiling?
7-Can you see a change in the people's attitude from the beginning? 
8-What do you think about this kind of events?
9- Do you know this music?
10- Opinion personal about this music.