The list of songs that I posted (aside from "Welcome back to town!") consisted of songs only in the GCN versions of Animal Forest. Therefore, they were only "missing" because they weren't in the N64 version to begin with. And "Welcome back to town" is a song that has multiple tunes to it, just like Dire Dire Docks in SM64. The main tune is "Totakeke's Intro", and the other tune is "Welcome back to town", which hasn't been ripped.
Don't bug HCS about it. :P And now, I go back to my Excel Saga. ~Supakitsune
I just checked out the system involved in muting channels in Animal Forest, but it appears that there's a hard-coded system used to not play some of the instruments in the one song that needs it
800FB148 is where the decision is made about which song is played. Since it's not running on the title screen, I'm guessing it wouldn't be included in the the rip.
In the game, here's the practical codes to duplicate the effects: Less Instruments: 80274247 0040
More Instruments: 80274247 0076
Only have them enabled while on the New Game screen. Other areas of the game don't use the address for music purposes.