Chinese here. Metal scene has been growing really fast these few years, metallica's first show sold out in minutes, so they added a second one which is tonight. It's whole new scene compared to what it was like five years ago. In 06 or 07 they had Rolling Stones played there, and had the Chinese rock guy Cui Jian opened, what been reported is many people left when CJ finished his set.
It would be so awesome to see many other bands will consider China as a good market after metallica's visit. Cheers