Music taking up storage both in documents and iTunes?

So I'm looking at my storage, and it seems that the music I have for iTunes which is found in my documents is taking up space both in documents as well as in iTunes? So it seems that the space it is taking up is being doubled for some unknown reason, any help? I can't find anyone else with this problem.

As you can see, 89gb is taken up in documents but 80gb of this is music, and the 'iTunes' tab on the left also shows 70gb being taken up, so essentially the space being taken up by music has doubled, I have removed music from iTunes and both the 'iTunes' section and 'Documents' section storage have reduced equally, leading me to believe the laptop has doubled the music I have downloaded or something? Any help would be much appreciated, thanks.