I think the trick is to just select "sort by Title" - then all music shows (I'm a complete novice of course)
nope. you can't sort nothing. if you sort nothing by artist field, it is still nothing, and if you sort nothing by title, it's still nothing. if you see -absolutely nothing-, you can't sort it. the problem was, the entirety of the mp3s were NOT showing at all. not a single song. nothing. it was there a day before, and then *bam*, gone, all gone, nothing at all showing up. because the new setting came up, "apple music", whatever that is, probably they want to become a new spotify or what not. unchecking the option to show that "apple music" thing did the trick, as it reverted back to the normal music library view