I think there are different types of reason behind.
The voice of China one I think are paid actors.
As for concerts, I shall comment based on own personal experience.
I admitted I cried (but inside the heart) and not showing it, becos of a certain kind of uncontrollable thoughts and emotions like am I dreaming or real? The concert was the beyond 活得更精彩 1996. Since young I tried to imitate 1 of its member, in terms of look, hairstyle, dressings and even picked up guitar becos of my idol.
So when I saw them performing live in front of me I just couldn't control my internal feeling.
KNN siao