Chinese opera is great. Most i would not put in the same sonic category of yo yo ma. I recommend a movie called To Live with Gong Li as actor
http://www.allmovieportal.com/b/gongli.html
This was probably my first good introduction to chinese opera which of course is not relaxing to most people.
There are many good Koto CDs...on the more traditional but modern I recommend Shoko Hikage. My favorite however is her teacher, Kazue Sawai who can go from traditional to out there on the same track.
new albion label also is pretty asian inspired. I would check out the recordings by David Hyke in particular an old time favorite recording of Jamchid Shemirani (iranian tabla player) with david hyke.
enjoy it....mehran