I would like to request a hack that disables music during WFC voice chatting in HG/SS. The music sometimes interferes with properly hearing the person.

You mean like an Action Replay code? I don't think anyone here knows how to make them... Correct me if I'm wrong.

I mean like a ROM patch, or a hex edit for the ROM.

You can't connect to WFC from a ROM on an emulator... Unless you're using something like an R4 card. Which is illegal...

Search 'IR Tweaker' on Google.It surely will help you.

Regarding flashcarts and this forum's policy: flashcarts themselves work just like emulators, they only play what you put on them, since emulators are exempted from the forum's definiton of copyright infringement, why would flashcarts be treated differently? The forum rules outlaw only "copyrighted items", with no mention of "ways to run copyrighted items" being outlawed. In which case emulators would have to be outlawed aswell.

Go check the DeSmuME forums on NGemu. They got WiFi support working in the latest builds.

Also, IR Tweaker doesn't seem to be what I am looking for... how do I edit the music for a certain are of the game? Is there any tool? That should be what I need.