Playing music that you dont hold a broadcasting licensee too while on stream is copyright infringement, so comes under the you cant stream copyrighted content tos. However cb mostly turns a blind eye to music when it's in live streams, I can almost guarantee that no one on any live streaming site is paying the broadcasting license, for 90% of streamers it wouldnt make financial sense to do it.
This does trigger a warning, even having a tiny portion of a screen with a video on it will trigger a warning and eventually a ban. So if your video feed showed like your profile picture here is where there is a tv with an image displayed, it dosn't matter what the content on the screen is you'll get a warning. I used to have a spare tv behind me that played trailers for my videos on a loop and had a copyright warning for that too. Best thing to do imo is make sure that any screens that are not your chat are turned off.
CB is super inconsistent in allowing some copyrighted content but not other copyrighted content.
It used to be having the spotify info showing on screen would trigger a warning (dont know if it's still the case but I have seen it more and more over the last year or so).