WOOH! After about 30 minutes of digging through MC's assets folder and trying different file names I got it working. Thanks so much!
I'm trying to make a sound that when called plays some of the music (like calm3) from the game, but I don't know how to create that SoundEvent short of adding the music I want as part of the mod's assets, which I would like to avoid for obvious reasons. Unfortunately, the sounds I want to play are all grouped together in a single vanilla SoundEvent, so I have to make my own for this one. Can anyone help me with that? Currently working with Forge 1.15.2-31.1.0