Pokémon BDSP music modding is possible, though I don't recommend it.

First, credit to insaneintherainmusic and the many talented musicians who made the "Sinnohvation" album possible. (if you see this i could def use some permission to upload the mod publicly if you're cool with that aha........)

So, it's possible, but unless somebody manages to make a tool (I'm not smart enough to reverse-engineer a file format lol) that can simplify the process, music replacement in BDSP consists of meticulously hex editing the game's main soundbank and hoping that nothing breaks. Route 201 and Twinleaf Town have it a little easier since I set them up to loop from start to end, but even that's a nightmare to work with.

I wonder how I'm going to handle replacing 40+ tracks lol. Hopefully it'll be second-nature in, like, a week.

My copy arrived early btw :)