Source: VGM or Chiptune news
On the Illusion City website a new section has been added about the YM2413, also known as the Yamaha OPLL sound chip, as used in the MSX-MUSIC (FM-PAC) standard. On this page you can find data to create nice YM2413 sounds, and some BGM files (musica) that demonstrate the sounds.
Relevant link: YM2413 voicebank