A few months ago, I discovered a channel called Video-Game OST HQ, which has a bunch of N64 music in high quality, better than what you can hear from the original game. They have both regular and HD+ versions of the music. The HD+ versions seem to have some virtual surround sound added to the music. They somehow get access to high quality versions of the audio samples from these games, and use it to reconstruct the music to use these high quality samples. According to their YouTube channel:
“Everything here was recorded with new methods from scratch. These are not game/CD/vinyl/etc. rips, nor were they made from USF files or SoundFonts. USF files are like taking the synthesis engine out of the game, whereas my process is more like giving the game a whole new engine that has been super charged. In many cases the original composers/developers provided direct assistance, and all videos adhere to all Nintendo guidelines. The goal is to preserve these songs in a crisp clear format that should stand the test of time a little better. WAV downloads available in most playlist descriptions.“
You can find more uploads on the YouTube channel as well as links to WAV versions of some of the music uploads. For the ones that don’t have them though, it will link to where you can buy the OST from the original composer if they’re selling it.
I think this is really cool because while preserving the original sound is great, I think preserving the music in the best possible quality is great as well. I also just love having a way to listen to N64 game soundtracks in a higher quality than what they could do on the system.