@macforthewin
General point: We add music to the iPhone by checking playlist/albums/songs(etc) in iTunes and then click APPLY.
If it says SYNC, then you have not changed any choice of boxes (but a playlist may need to be updated with a SYNC, eg extra songs).
@macforthewin - you said there was no APPLY, so I assume you made no changes. Are all music boxes unticked?
So, you need to connect to iTunes and make sure you UNTICK all ticked boxes in the music section on the iPhone. There are many sections, eg. Playlists, Albums, Songs, Artists etc. Make sure ALL of them have NOTHING ticked. Then press APPLY (assuming you have made at least one change).
Unless you do the above, you cannot delete the data from this route:
Settings >> General >> iPhone Storage >> Music (not "Photos" as I wrote earlier!)
But if you have unticked all music, iPhone does allow you to delete the data that is there, because it's the music+artworks are connected to anything in iTunes.
In my experience, it was because all the music and data was transferred to a new phone. Then iTunes got confused when making a change for the first time on the new phone.
So if all is unticked you can delete the data in Settings >> General >> iPhone Storage >> Music
Maybe restart and then check the storage of Music in Settings is zero.
Then re-connect to iTunes, tick the choices you want and press APPLY. That should be it.