Apple Music downloads.

I am having problems with my Apple Music downloads. I was looking at my storage, and saw that my downloaded playlist of around 1200 songs was using up 34 gigabytes of storage. The problem, however, is that my friend has the same exact playlist downloaded on his iPhone, but it is only using up 10 gigabytes for the same playlist of 1200 songs. My question is why my iPhone is having this take up 3 times more space than my friend’s iPhone? I suspect that I may have downloaded a higher quality version of these songs, which is why it has taken up so much space. If so, is there any way to transfer over my current high quality downloads to the lower quality ones? Or will I have to delete all my downloads and redownload the lower quality ones? If that’s the case, is there an option in settings to disable the iPhone’s ability to download these higher quality versions? Any help would be greatly appreciated. Thanks!