It seems like C:BN does not respect music volume from json, and if you go into the settings, change anything (not even related to volume), the current playing music volume will be overriden by the volume from thettings.
Same thing happen when you just start the game, i guess, because music is loud (if set to 100%), and the next track from playlist will be with the volume from json... until you again change something in game settings.
Just tested with every track set to 100% and ingame music volume at 100, i don't have issues anymore:
![image](https://user-images.githubusercontent.com/2702567/153687196-89f1f40d-143a-4b14-9e5c-6c29218af7ef.png)
Btw, not sure why some tracks set to 20% and some to 70%+, most of them are of the same volume:
![image](https://user-images.githubusercontent.com/2702567/153687672-9a7b67e9-3a6f-41fc-ab34-51ab35d8c6c8.png)
Tracks from that screenshot has 20 and 70 volume accordingly, but as you can see, second one has even higher peaks. I might guess, why did that happen: the person, who adjusted those volumes either forgot to change json volume settings after sound file normalization, or just adjusted them by just using poorly configured sound equipment. The second one is very loud on the lower frequencies (or just of a poor quality/mastering), that way it might sound less louder, on the systems with quiet low frequencies
Anyway, i'm not sure if overriding volume issue is a problem from Bright Nights, maybe we should report it to their github, but also i suggest to change volumes with more respect to their actual loudness, which is always better to get from sound wave visualisation tools, if you have no studio equipment. I recommend Audacity, this one can be used to easily normalize tracks as well. Just Ctrl+A it, and use that feature:
![image](https://user-images.githubusercontent.com/2702567/153688555-f4fbbde8-d89b-47ac-a8e8-d471a264d3ee.png)
Quick tests shows that right now files are already normalized to about from -12 to -14 dB
Thanks for the good sound pack btw!