I'm quite happy. Today I've finished a simple music sequencer that uses the PSG to generate music, and you can use BASIC Music Meta Language (MML) to generate music. I is quite simple and I'm sure it can be improved, but at the moment you can add music in a very simple way.

But I don't like the PSG sound right now. It doesn't sound very old school. It generates triangular waveforms, and it should generate square ones, like good old micros did. I think this will be the next thing I'll do.