photos slideshow wont let me add downloaded itunes music
I am trying to make a slideshow on photos for me and my family to look at, but it won't let me add my iTunes music and is just grayed out. The song I was trying to add is apple music but downloaded to my computer. At first I just thought that it was because it was apple music and went to add some music that I own, and found that this music was also grayed out. All of them are downloaded to my computer. Is there any fix to this problem? was trying to make a nice slideshow for my mom to her favorite song for her birthday.
Macbook (2016 or later)