Why can't I access all my music after Migration?

Thank you, Jim, for the good advice. I did each thing you suggested but I'm still not getting every song from my old list of songs in the "Music" app to show that it's available to download into the Library. Looks like maybe 5 - 10% of songs are still gray and showing only a dotted-line cloud icon. If I click on a grayed out song and then on the little "playing next" icon in the upper right, it opens and there's a red "negative" mark ("-") on the title as if to say, "You shall not play this song!" I guess I can go through the list and re-import them (most of the grayed out titles were imported from CDs). But so much of my music that did migrate also originated on old CDs. Hmm...