FamiTracker

Gameboy can't change square wave volume without resetting the phase of the wave (clicks and metallic buzzing). It can do it in a limited way with volume envelopes though, it can strictly decrease or increase volume at a regular rate with no buzz artifact. It's a different beast entirely. So your GB ...

VS Ice Climber had different music.

Square wave phase reset happens when you write to the high byte of the wave period, so if the high byte changes, you get a phase reset. However, it is also possible to use the frequency sweep function to change the high byte of the wave period, so you can avoid a phase reset on a real NES. Famitrack...

Here's one I did a long time ago:

Where's the file?

Still wrong notes in the accompaniment.

The notes are not all correct, and it's very annoying.

This is where you can seriously see the lack of pitch effects when combined with arpeggios. Seems like only explicit fine tune commands would work here.

What's that C0 doing in there?

There was a nice Romhack (Mario vs. Air Man) that also used this music.