FM Synthesis Libraries

I'm thinking about using a realtime FM synth for music and sound effects in my next game. I'd write a library myself, but I don't want to waste my time if there's already something good out there. The thing is, google turned up no results. Am I going to have to get cracking on my own?

Nintendo still leads with the best sound in there games. They now use live Orchestras for there music, and if you want an uber bad ass game I suggest you do the same.