Being a Dutch tenor (singer) I am used to the fact that there is usually a pin drop silence from the audience while a concert is in progress. And one is expected to stay seated during the performance and visiting the toilet is also restricted to the interval only.
I recently visited East China (region of Shanghai) where I participated as a soloist in a couple of concerts. There it seemed more common for the audience to walking in and out for smoking or going to the bathroom, talking to one another in medium voice and also keeping in touch with their telephone while listening to the concert! In plain view of the people who are trying their best to make the evening worthwhile. Something that would have been a pretty culture shock to me, had it not been for the fact that I had been already warned about this before I started the concert. So what I had heard was just being played out before me. As a matter of fact I found it all very amusing as I went on performing. After the last tone sounded an ovational applause overwhelmed us and pictures/films were taken and autographs had to be given. Crazy.