Interiors and the menu song don't seem to be affected, but out on the streets I have to strain my ears to hear the music. I'm still too early in the game to check the other hubs, but it's definitely different from previous playthroughs. Do you think it's a bug or did the unofficial patch's creators mess with the audio levels?
Seeing as how there's only one volume slider, is there some way to individually change how loud voices, effects and the music can be heard? Thanks.

I didn't do anything to the music on purpose and I don't think you can globably modify it apart from the other sounds.