Wow pretty catchy, although I'm surprized you didn't rely on the quick waveform swapping to produce "noise" with randomly generated waves.
There's two "tiers" of expansion chips in my opinion.
There are chips like MMC5 or VRC6, which only add something to the exising channels, but they're not much by themselves.
And then there are chips like the N163 or the VRC7, which can produce any element of modern music on their own. I believe 5B also belongs to this category, I mean think about it! It has its own noise generator for percussion, and the envelope generator for bass notes.
I guess one could conceivably make a VRC6-only entry (or a 5B-only entry once Famitracker supports it, or you're willing to put yourself through the torture of using ppMCK).
Yeah, I agree that the N163 and VRC7 work well on their own as standalones, though I can't really say too much about the 5B since I haven't played with it at all.
Never really thought of using the waveform as noise, but I'll take a dip into that in the future.
Here, feel free to use this any time! One thing to note though, is that thanks to the 60Hz refresh rate, it only works well below C-3. If you go higher than that, it'll sound like a buzzsaw instrument you hear in bad Genesis music. The high frequencies can be used like a periodic noise cymbal on the 2A03 though. You can also insert a pitch bent square in there for a frame of two to get C64-esque drum sound on a single channel.
Ultimately if you're really desperate, you can simply overclock your tune. Even 120Hz can do wonders here.
