There's a website called Neocha that acts as a sort of Chinese underground music equivalent to the MySpace of today, or the MP3.com of 8 or 9 years ago, connecting local bands with potential fans from across the region, and sometimes across the globe.  From LostLaowai's interview with the site's creator, Sean Leow:

When I first came to China in 2001, I was fortunate to meet some expats friends who were into the local music scene and also some Chinese friends who gave me really good music recommendations. Based on that, I started going to live shows and started to realize that there was good original music out there. But the biggest problem was — I had no good way to find out about shows. The information and content was not really aggregated anywhere. That’s one of the main reasons that we started Neocha.

All of this is fine and dandy, but if I were to take a wild guess, I would imagine that you, reader, probably can't read Chinese, making the website a bit of a slog to make your way through.  Not to fear!  Neocha created a self-contained, simpler than simple music player called NEXT that plays nothing but underground music from China pulled at random from its servers.  If something like this were being done by MySpace, I probably couldn't flee fast enough from the user content, but a majority of Neocha's music seems to be pretty top-shelf stuff (this Nina Simone/Jeff Buckley cover notwithstanding).  Most of the artist and song names are still in Chinese, but you can at least click on the album artwork and go to the artist's page and consult Google for answers from there.  If you've got the time and bandwidth to spare, NEXT is a great little program to have around, and if you don't like what's playing at any given time, you can simply click the giant "NEXT" button.  You'll probably find something you'll like.