Triangle was a lot quieter normally. The 5th channel was for wav files in a specific format (really REALLY low quality, i forget exact specifics, but usually used for drum samples).
If it's an IT, you've got a lot more room for experimentation, I meant Mario 2 and 3.
poop3 is just weird, i have no input, because I have no idea what it's even meant for.
I know what the NES had, my whole point wwas that there wqasn't enough variation in sound, all the tracks generally used the same sounds. People writing music for the NES took advantage of some of the more advanced parts of writing music on it.