Many of the good ones are self-taught or learned by private lessons.
There's nowhere in China that u can learn systemized professional skills of pop music, like the Berkley Music School in USA...
Another big problem is the students haven't been exposed to large amount of high-quality pop tunes at all, coz we're far from being OPEN enough. Thus sometimes they don't even know that they are producing Shit and Garbages, but anyway, who gives a damn to those good works in China?